Thank you!

Oh I love your wallpaper, do you have a link to somewhere I can download it?

Thats interesting, I am using lineage as well (oneplus 6t) and do have the app com.android.devicelockcontroller. This could be some junk added when I enable the gapps magisk module which I generaly keep dissabled though.

In addition to the other resources people have linked if you are interested in learning more about this type of scam take a listen to
Darknet Diaries episode 141: The Pig Butcher, it is very interesting.

Rooting is a slightly separate thing from sideloading a custom rom, rooting gives apps you give permission to access to system files whereas sideloading a rom replaces the system files but doesn’t necessarily give you root access. Both involve a similar process of unlocking the bootloader, installing a custom recovery and flashing a file so it is easy to get the two things mixed up.