I just made one yesterday (was sick of waiting for fanatec shifter to arrive so I bought g29 shifter to use now and have a backup)
Bought a Arduino leonardo and this from Amazon https://www.amazon.ca/dp/B07K56JYM7/ref=pe_3034960_236394800_TE_dp_1
Took a day to get here and watched am studios video how to make it.