Huawei BND-L21 Quick Start Manual page 96

Note: Remember the Google account your phone
last logged in to.
During an untrusted factory settings restoration or
microSD card–based update, Google's anti-theft
mechanism requires you to enter the Google account
your phone last logged in to on the startup
navigation screen for identity authentication. Your
phone can properly power on only after the identity
authentication passes.
Please visit
http://consumer.huawei.com/en/support/hotline for
recent updated hotline and email address in your
country or region.
31509290_01