Debian/Ubuntu
Edit/create udev rules (use vi, nano, or any text editor). * Note: The filename/order can be different as per personal preferences. 45-stdfu-permissions.rules is typical of most Cleanflight/Betaflight installations/documents.
sudo nano /etc/udev/rules.d/45-stdfu-permissions.rules
Copy/paste this content and save it: (See STM list here: https://devicehunt.com/view/type/usb/vendor/0483)
# All STMicroelectronics STM32 devices
SUBSYSTEM=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="****", GROUP="plugdev", MODE="0664"
# All Artery AT32 devices
SUBSYSTEM=="usb", ATTRS{idVendor}=="2e3c", ATTRS{idProduct}=="****", GROUP="plugdev", MODE="0664"