@PierreD
You can run the VisualStudio Code platformIO. It supports the M5Stack ESP32.
I have copied the M5_Stack_WiFi_Scanner demo arduino ino file into the platform io editor.
I downloaded the code to my M5Stack (black) and it worked.
Please play attention: In contrast to the arduino environement the VisualStudio Code PlatformIO is a one pass compiler, so you must place all subroutines (eg void Show(), Search()) at the beginning of your program (loop, setup ...) before they are called.
You can watch a PlatformIO tutorial for Arduino, ESP8266, and ESP32 made by Andreas Spiess on YouTube :
https://www.youtube.com/watch?v=0poh_2rBq7E
Good luck crami25