How to Install Custom ROM on Mi A2 or Any AB Slot Device

Hello,I've successfully installed twrp and rooted via experimenting with TWRP, I tried booting from the 'B' slot Failure, stuck in fastboot

From what I read, I should first boot into TWRP then flash it, else I will break things, correct? If I manage to basically dual boot my

yg 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 (

pg slot game 888 เว็บตรง เกม Card slot microSDXC Internal 64GB 4GB RAM, 64GB 6GB RAM, 128GB 4GB RAM, 128GB 6GB RAM UFS MAIN CAMERA Camera 50 MP, f, 26mm (