Best - Efrpme Easy Firmware

Some vendors now ship with "EFRPME compliant" firmware:

: EFRPME is often available for free, with a community of users and developers who contribute to its improvement and provide support. efrpme easy firmware best

If you see a blinking light after 15 minutes – you likely need a serial TTL recovery (still fixable). Some vendors now ship with "EFRPME compliant" firmware: