Unable to verify identity via phone number

[SweetKaym]

Every time I try to verify my phone number, it tells me that it's not supported. Why not? It's an AT&T postpaid phone account, and I'm the sole owner of said account. I don't understand why my phone number won't go through. It's not a Google Voice number or VoIP number but an actual phone number issued by AT&T. What can I do to resolve this on my own? I changed addresses (I live in New Jersey, recently moving from New York City). Any suggestions will be much appreciated😀

[Cfgtech]

I have this exact issue I was able to do it in the website but on the APP when linking my bank it does NOT accept my phone number, my provider is VISIBLE anyone figure this out? I'm contacting customer support