For advanced users only: Some ZTE devices (especially the ZTE Z839) have "test points" on the motherboard. Shorting these points forces the phone into "EDL mode" (Emergency Download), allowing you to flash a clean engineering ROM that has FRP disabled. This requires a screwdriver, tweezers, and a Windows PC.
The ZTE Blade 2 (ZTE2) is particularly tricky because older Android versions (6.0–7.1.1) have known FRP bypass vulnerabilities — often . bit.ly frp-zte2 google play services