Can't make app login with C#


Dear Sir,
When we submit code with this link, we see problem:

Can you check it? And i can’t upgrade to the current permissioning system. they ask me provide mobile phone. But when i provide my phone they said that “Sorry, we don’t have a connection to your carrier yet!”.
I’m come from Vietnam. This is my phone {redacted}. My Carrier is Vinaphone.

My Developer account:
Username: nguyenducthomc2
pass: {redacted}