Me and a friend of mine figured out how to do a HTTP post with parameters in micropython. Me used it for sending SMS, but it can be modified to anything else.
https://forum.m5stack.com/topic/1902/http-post-from-arduino-esp8266-esp32-how-to-send-parameters-x-www-form-urlencoded-using-micropython/3

My friend and colleague programmed this..

https://github.com/46elks/46elks-getting-started/blob/master/code-examples/MicroPython/https_post_with_micropython.py
If you would like to use 46elks Telco API mentioned in the code, register here and contact us at help@46elks.com for help.

# Rudimentary HTTPS POST request using MicroPython without any 
 dependencies.
 # Supports Basic Auth and encodes data as x-www-form-urlencoded.
 #
 # Written by Johannes Ridderstedt <johannesl@46elks.com>
 # This code is public domain. Use freely.

 from ubinascii import b2a_base64
 import usocket
 import ussl
 
 # API credidentials
 username = 'u2c11ef65b429a8e16ccb1f960d02c734'
 password = 'C0ACCEEC0FAFE879189DD5D57F6EC348'
 
 def quote( value ):
   l = []
   for ch in value.encode( 'utf-8' ):
     if ch == b' ':
  l.append( b'+' )
elif ch > 32 and ch < 128 and ch not in b'?=':
  l.append( b'%c' % ch )
else:
  l.append( b'%%%02X' % ch )
   return b''.join( l )

 def api_post( path, data ):

   info = usocket.getaddrinfo( 'api.46elks.com', 443 )
   ip = info[0][-1]

   args = []
   for key in data:
args.append( quote( key ) + '=' + quote( data[key] ) )
   content = b'&'.join( args )

   lines = [
b'POST /a1/%s HTTP/1.0' % path,
b'Authorization: Basic %s' % b2a_base64( username + ':' + password )[:-1],
b'Content-type: application/x-www-form-urlencoded',
b'Content-Length: %d' % len( content ),
b'',
content
   ]

   conn = usocket.socket()
   conn.connect( ip )
   conn = ussl.wrap_socket( conn )
   conn.write( b'\r\n'.join( lines ) )
   print( conn.read(4096).decode('utf-8') )
   conn.close()

 sms = {
   'to': '+46704508449',
   'from': 'MicroPython',
   'message': 'Hello from MicroPython!'
 }
 api_post( '/sms', sms )

I don't have ANY experience with micropython..but I would like to use blockly features of UI flow for development thus I would appreciate if anyone could help me out how to translate this simple http post with parameters into micropython?

  http.begin("https://api.46elks.com/a1/sms");
  http.addHeader("Content-Type", "application/x-www-form-urlencoded"); 
  http.setAuthorization("XXXXX", "YYYYYY");
  int httpCode = http.POST("'from:+XXXXX','to:+XXXXX','message:Hej'");

Here is the rest of the code! Thank you!

#include <M5StickC.h>
#include <Arduino.h>
#include <WiFi.h>
#include <WiFiMulti.h>

#include <HTTPClient.h>

#define USE_SERIAL Serial

WiFiMulti wifiMulti;

void setup() {

USE_SERIAL.begin(115200);

USE_SERIAL.println();
USE_SERIAL.println();
USE_SERIAL.println();

for(uint8_t t = 4; t > 0; t--) {
    USE_SERIAL.printf("[SETUP] WAIT %d...\n", t);
    USE_SERIAL.flush();
    delay(1000);
}

wifiMulti.addAP("YYYY", "ZZZZZ");

}

void loop() {
   // wait for WiFi connection
if((wifiMulti.run() == WL_CONNECTED)) {

    HTTPClient http;

    USE_SERIAL.print("[HTTP] begin...\n");
    // configure traged server and url

      http.begin("https://api.46elks.com/a1/sms");
      http.addHeader("Content-Type", "application/x-www-form-urlencoded"); 
      http.setAuthorization("XXXXX", "YYYYYY");
      int httpCode = http.POST("'from:+XXXXX','to:+XXXXX','message:Hej'");

    USE_SERIAL.print("[HTTP] GET...\n");
    // start connection and send HTTP header
     httpCode = http.GET();

    // httpCode will be negative on error
    if(httpCode > 0) {
        // HTTP header has been send and Server response header has been handled
        USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);

        // file found at server
        if(httpCode == HTTP_CODE_OK) {
            String payload = http.getString();
            USE_SERIAL.println(payload);
        }
    } else {
        USE_SERIAL.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }

    http.end();
}

delay(10000);
}

Thanks for the reply
Found the tutorial too!
http://forum.m5stack.com/topic/42/lesson-2-buttons-menu

I would like to have it so a get request with arguments gets run when an action is made, for example pressing button A or B. I'm new with M5stickC and don't know how to do that.
This is the code for sending a SMS with a delay... but executing a API call with a button is unknown for me...

 #include <M5StickC.h>
 #include <Arduino.h>
 #include <WiFi.h>
 #include <WiFiMulti.h>
 #include <HTTPClient.h>
 #define USE_SERIAL Serial

WiFiMulti wifiMulti;

void setup() {

USE_SERIAL.begin(115200);

USE_SERIAL.println();
USE_SERIAL.println();
USE_SERIAL.println();

for(uint8_t t = 4; t > 0; t--) {
    USE_SERIAL.printf("[SETUP] WAIT %d...\n", t);
    USE_SERIAL.flush();
    delay(1000);
}

wifiMulti.addAP("xxxxx", "xxxxxx");

}

void loop() {
// wait for WiFi connection
if((wifiMulti.run() == WL_CONNECTED)) {

    HTTPClient http;

    USE_SERIAL.print("[HTTP] begin...\n");
    // configure traged server and url

      http.begin("https://api.46elks.com/a1/sms");
      http.addHeader("Content-Type", "application/x-www-form-urlencoded"); 
      http.setAuthorization("xxxxx", "xxxxxx");
      int httpCode = http.POST("from=+xxxxx&to=+xxxxxx&message=Hej");


    USE_SERIAL.print("[HTTP] GET...\n");
    // start connection and send HTTP header
     httpCode = http.GET();

    // httpCode will be negative on error
    if(httpCode > 0) {
        // HTTP header has been send and Server response header has been handled
        USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);

        // file found at server
        if(httpCode == HTTP_CODE_OK) {
            String payload = http.getString();
            USE_SERIAL.println(payload);
        }
    } else {
        USE_SERIAL.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
    }

    http.end();
}

delay(10000);
}

After running this code, I get no errors only a blank screen. Could anyone tell what I did wrong at first glance?

from m5stack import *
from m5ui import *
from uiflow import *

fields = {
'from': 'PythonElk',
'to': '+XXXXXXXX',
'message': 'Test Message To your phone.'
}
try:
req = urequests(
method='POST',
url='https://api.46elks.com/a1/SMS',
headers=fields,
data={'XXXXXXXXXXXXXXXXXXXXX',' YYYYYYYYYYYYYYYYYYYY'}
)
except Exception as e:
print(e)
import urequests
import ujson
setScreenColor(0x111111)
auth = (
'XXXXXXXXXXXXXXXXXXXXXXXX',
'YYYYYYYYYYYYYYYYYYYYYY'
)
fields = {
'from': 'PythonElk',
'to': '+XXXXXXXX',
'message': 'Test Message To your phone.'
}
headers = {'Content-Type': 'application/json'}
try:
#urequests.request(method='POST', url='https://api.46elks.com/a1/SMS', auth, fields,headers
post_data = ujson.dumps('XXXXXXXXXXXXXXXXXXXXXXX','YYYYYYYYYYYYYYYYYYYYYYYYYYY')
request_url = 'https://api.46elks.com/a1/SMS'
res = requests.post(request_url, headers = {'content-type': 'application/json'}, data = post_data,json=fields)
print(res)

req = urequests.request(method='POST', url="import urequests setScreenColor(0x222222) fields = { 'from': 'PythonElk', 'to': '+XXXXXXX', 'message': 'Test Message To your phone.' } try: req = urequests.request( method='POST', url='https://api.46elks.com/a1/SMS', headers=fields, data=('XXXXXXXXXXXXXXXX','YYYYYYYYYYYYYYYYYYYYY') ) except: print(req.status_code)",json={'user':'a'}, headers={})

except Exception as e:
print(e)