Changes

FMD uses 2 different apps, FMD-Firefox Accounts Settings/FirstTimeUse gecko level code. Which is what you use when you sign into firefox accounts. You can modify this endpoint by pushing user_pref onto your b2g device.

Find My Device - Settings has two endpoints: fxa-oauth and fmd app server which is in the Gaia layer. You can modify this endpoint by flashing a locally modified findmydevice.json Gaia to your phone.