At the time of writing, the ATTINY212 is currently available at Digikey.
First, install these libraries:
https://github.com/SpenceKonde/megaTinyCore
https://github.com/contrem/arduino-timer
Configure as shown:
Programming can be done with a UPDI programmer and 3 jumper wires temporarily inserted into the board.
Burn the bootloader once to program the fuses. Then upload the sketch.