you can read these info from the packaging box!
I managed to fix my issues (i believe) by continuously flashing and flashing versions. I never really managed to fully OTA update to 100% due to some "CUST error" but from B350 i managed to "update" ...
by the way, if you want to get the unlock code but mobile registration isn't avaiable for your country, you can still get the sms by editing the source code of the request form by pressing f12 on chrome and hardcoding your phone number and your pr...
you guys can also follow this guide if you want: