Step-by-step – Arduino IDE Installation in Ubuntu 20.04 Guide

Getting Started

4. 4. Launching Arduino IDE

   Finally, Launch & Enjoy Arduino IDE
   Use the Desktop Launcher:

   
   Of from Shell with:

   flatpak run cc.arduino.IDE2

   The Flatpak build of Arduino IDE 2.x requires the user to have USB permissions to upload a sketch, preferably, the user has to be part of the dialout group.
   Alternatively, add the following 2 lines to /etc/udev/rules.d/50-arduino.rules.
   With the nano Editor:

   sudo nano /etc/udev/rules.d/50-arduino.rules

   Copy and Paste the below Contents:

   KERNEL=="ttyUSB[0-9]*",MODE="0666"
   
   KERNEL=="ttyACM[0-9]*",MODE="0666"
   

   Ctrl+Shift+v to Paste in with nano.
   Finally, Ctrl+x to Save & Exit from nano Editor.

5. 5. Arduino IDE Getting-Started

   Getting-Started with Arduino IDE on GNU/Linux

   Arduino IDE QuickStart Guide

   Getting-Started with Arduino IDE on Ubuntu Tutorial