How can I get past the trusted number when resetting the iCloud password on iPhone?

My daughter can no longer access her emails or log into iCloud so I think she may have been hacked. I’ve tried to reset the password but I can’t get passed the trusted phone number stage as it doesn’t recognise the number. How can I get passed the trusted number section when resetting the iCloud password if it doesn’t recognise the trusted number?

[Re-Titled by Moderator]