You can try this :
Go into TWRP (the recovery mode) by turning off your phone, and pressing Home + Power + Volume Up buttons for 7 seconds
Once you are in the main menu of TWRP, go in Wipe > Advanced Wipe > select “data” > Repair or > Change File System > Change File System > ext3 > swipe to confirm.
Re-do the same steps again but select “ext4” instead of “ext3”.
TWRP main menu > Reboot > System.
Just tried this, I still have the black screen when rebooting
FYI, it’s already available.
I also just tried this build e-0.9-p-20200605-UNOFFICIAL-j5lte, but unfortunately the result is still a black screen.
For each of these builds I get an error 7 when installing from TWRP, which I remove by using following this tutorial. But finally maybe my phone model is specific and just not compatible with these roms.