Install Magisk via TWRP - problem with slots

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

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

samurai slot png TWRP Recovery, flash the Jaguar ROM, root your device via Magisk Slot B 19:08 Flash

real slot apps 3:32 Go to channel · What's AB Partition System - Android