Amazon FBM – Does Amazon provide real customer phone numbers?

I do Amazon FBM, all B2B, and noticed a customer provided a 5 digit phone extension which doesn’t seem right. In this industry, you usually just have a phone number (solo operator) or, rarely, a 3 or 4 digit extension.

I Google’d the number, and it appears to be used by scammers. However, on Amazon seller forums, someone said these are Amazon numbers that transfer to the customer’s real phone number.

I’m looking to see if this is actually true or not and where would I confirm this?

The number I got starts with 929-436, a NY area code which the customer lives in the midwest.

The only information I could find out is that it is a VoIP and from Bandwidth.