I am trying to use the FLow/Blocky interface to read a remote ICS file. It needs a python module. How do I do this please? I get a error "no module names icalendar"

import urequests
from icalendar import Calendar
from datetime import datetime

def download_file(url):
    headers = {
        'User-Agent': 'MicroPython'
    }
    response = urequests.get(url, headers=headers)
    if response.status_code == 200:
        file_contents = response.content
        return file_contents
    else:
        return None

def parse_ics(ics_data):
    calendar = Calendar.from_ical(ics_data)
    current_meeting = None
    next_meeting = None
    now = datetime.now()

    for event in calendar.walk('vevent'):
        start_time = event.get('dtstart').dt
        end_time = event.get('dtend').dt
        if start_time <= now <= end_time:
            current_meeting = event.get('summary')
        elif start_time > now:
            if next_meeting is None or start_time < next_meeting['start']:
                next_meeting = {
                    'start': start_time,
                    'summary': event.get('summary')
                }

    return current_meeting, next_meeting

# Example usage
ics_url = "http://example.com/meetings.ics"
ics_data = download_file(ics_url)
if ics_data is not None:
    current_meeting, next_meeting = parse_ics(ics_data)
    if current_meeting:
        print("Current meeting:", current_meeting)
    else:
        print("FREETIME")
    
    if next_meeting:
        time_until_next = (next_meeting['start'] - datetime.now()).total_seconds()
        print("Next meeting:", next_meeting['summary'])
        print("Seconds until next meeting:", time_until_next)
else:
    print("Failed to download the ICS file.")