Why can't I verify my phone number?
The phone verification is done by a third-party service, and we have no control over the processing of requests. In our experience with other users, it sometimes takes several attempts over the course of a day to get through. Try every few hours for the next day.
There is no requirement to verify your phone to use Zello except under two conditions:
1. You are trying to create a channel
2. You are trying to join a channel where the owner has requested phone verification before users can join. The owner can turn off this requirement in order for you to join and then turn it back on.