Well, that was quick. Their exact reply:
“It looks like this was not enabled for your account, I have enabled this now and you should be able to allow the phone callback option via policy and authenticate to Duo using this method.”
I have verified it...
I opened a support case for this since it doesn’t look like we’re getting an answer here. Case 01154981. I’ll update this thread when I have more info.
I just signed up for an forum account to ask this exact same question. We are Duo Beyond, using the Universal Prompt, we have lots of credits, and the users I’m testing with have landlines defined.
Watching.