Boot custom ROM - Android

[Android Central Question]

Hello,

How can i boot up custom ROM Android like (LineageOS) ?
Do i need to have change something inside boot.img / or something command?

Note:
Phone (Umidigi Power)
Android 9
Unlocked bootloader,
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img

What i want is:
1. I want a Custom OS like (LineageOS)
2. Install another ROM or fix the stock ROM

What i found out.
1. After flash a system i got bootloop, see umdiigi power boot logo and reboot
2. Stock ROM / deos not work anymore before i get black screen
3. use alot of commands and nothing working
4. try to install system from TWRP but bootloop

Questions is (I think):
How i can fix it or install custom OS

Can you help me?

Thanks for your time

 

[mustang7757]

Best place would be xda forum.

If you have further questions
I'll leave a Link to register so you can communicate here as a guest account you can only post questions but can't reply.
https://forums.androidcentral.com/showthread.php?t=409154