This Device Is Locked Due To An Overdue Installment Payment Xiaomi -

And he never, ever bought anything on installments again.

The carrier can blacklist your IMEI, blocking the phone from using any cellular network globally. And he never, ever bought anything on installments again

The XDA Developers forum explicitly prohibits posting FRP bypass content due to potential legality issues. And he never

: Performing a factory reset (via Recovery Mode) will not remove a payment-related IMEI lock; it may actually trigger a secondary "Mi Account" lock that is even harder to bypass. And he never, ever bought anything on installments again