If your error has something to do with the "ADC1_GPIO35_CHANNEL not defined" error I got, then you can "simply" insert this
#include "soc/adc_channel.h"
into the
\Documents\Arduino\libraries\M5EPD\src\M5EPD.cpp.

I wrote this in a new line (line 4)

It's caused by a change from espressif 3.3 to 4.4.

Have fun, undefined

hmm, I can compile let's say the M5EPD Hello World example just fine.

Care to share the compiling error you're getting?

Thanks
Felix