This firmware from the community (Youtuber Kersey Fabrications)

Product Listing (Store Link)

DREMC SKR Mini E3 V3.0 include 1x JST Header + Pin and also ferrules. [Tools not included]

Install and Overview Video:

KF Firmware ( This is only provided as guide, make sure you select correct firmware)

All source can be found here: Select the branch you need from the drop down.