Flash Guide LineageOs - A/B devices

1) Download the boot.img and vendor_boot.img and ROM

2) Install the ROM's recovery using :

3) Boot into it using the power + volume up button or

4) Wipe data/factory reset

5) In aosp recoveries you have to go into Apply update and choose your preferred option.

6) On your PC with the downloaded ROM, type in the terminal:

7) Optionally you could flash Gapps or other packages which you'll have to reboot back to recovery (with the option given after flashing the ROM) and repeat steps 5 and 6.

8) Reboot and enjoy