here is my current uglyass DigiSpark initial setup ( Linux Mint 21+ )

digispark-setup-sheet.sh

A. Import Digistump Board Manager
#################################
- File >> Preferences
- Additional boards manager URLs: http://digistump.com/package_digistump_index.json
- Restart
- Tools >> Board >> Boards Manager >> Digistump AVR Boards >> Install
- Tools >> Board >> Digistump AVR Boards >> Digispark (Default - 16.5mhz)
- Close
  
B. Install Dependencies
######################
- usermod -a -G dialout [username] && reboot
- sudo apt-get install build-essential libusb-0.1-4 libusb-dev

C. Update Micronucleus Boot Loader & Rules
##########################################
- cd ~/.arduino15/packages/digistump/tools/micronucleus/2.0a4/
- cp micronucleus micronucleus.old
- cd ~/
- git clone https://github.com/micronucleus/micronucleus.git
- cd micronucleus/commandline
- make
- cp micronucleus ~/.arduino15/packages/digistump/tools/micronucleus/2.0a4/
- sudo nano /etc/udev/rules.d/49-micronucleus.rules
  # UDEV Rules for Micronucleus boards including the Digispark.
  # This file must be placed at:
  #
  # /etc/udev/rules.d/49-micronucleus.rules    (preferred location)
  #   or
  # /lib/udev/rules.d/49-micronucleus.rules    (req'd on some broken systems)
  #
  # After this file is copied, physically unplug and reconnect the board.
  #
  SUBSYSTEMS=="usb", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666"
  KERNEL=="ttyACM*", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666", ENV{ID_MM_DEVICE_IGNORE}="1"
  #
  # If you share your linux system with other users, or just don't like the
  # idea of write permission for everybody, you can replace MODE:="0666" with
  # OWNER:="yourusername" to create the device owned by you, or with
  # GROUP:="somegroupname" and mange access using standard unix groups.
- sudo udevadm control --reload-rules

base source: https://startingelectronics.org/tutorials/arduino/digispark/digispark-linux-setup/