How to FLASH CUSTOM ROM on AB Partition

How to Install Custom ROM on Mi A2 or Any AB Slot Device twrp slot a slot b Inactive slot is flashed during an OTA update while the OS is running on active slot, without distribing user's workflow If flashing goes well champagne slot twrp,how to flash custom rom on Mi 11x,ab partition How to change Android system boot

bigcoin slot Card slot microSDXC Internal 64GB 4GB RAM, 64GB 6GB RAM, 128GB 4GB RAM, 128GB 6GB RAM UFS MAIN CAMERA Camera 50 MP, f, 26mm (