They claim to be "finance for the next billion" and ship a module that can be preloaded on OEM's phones (and placed into the Android 'nondisable' list) to allow the phone to be heavily restricted after you enable the "Payjoy lock" as a condition of financing for either the phone or some kind of microloan.
The one place I saw this being used in the US was Samsung phones being sold by Rent-A-Center; a lot of pictures of old Galaxy phones being disabled after the rent-to-own lease had expired or payment had lapsed are out there, too.
Also, a Google module for the same has been available for a while - https://9to5google.com/2020/11/07/google-device-lock-control...
I guess people finance other luxuries, too—rims are a great example—but those don’t seem to require digital repo men.
It's also to reuse the phone later as collateral again on another microloan, almost like digitally pawning the phone off for twenty bucks each time.