The Fly-EasyERCFbrd v1.1 can be purchased from AliExpress https://s.click.aliexpress.com/e/_Dk0U9gN
This link is affiliated URL. If you purchase via link above it will give tiny cent of commission to the community organizers. (We are not Mellow employees, just 3D printer enthusiasts) This will not hurt your wallet and at the same time help us to maintain the GitHub better.
Klipper information can be found here https://mellow.klipper.cn/#/board/fly_ercf/
For Klipper support please join this Discord Channel https://discord.gg/zAung88zbK