Operator and Directory Assistance is ending
On or after January 1, 2023, you won't be able to use these services
on AT&T Phones.
Operator and Directory Assistance won't be available on AT&T Phone(sm)
(formerly U-verse(r) Voice) starting on or after January 1, 2023.
Because of this, you won't be able to dial 411 on AT&T Phone(sm) to
request phone numbers or addresses. Also, when placing calls, you'll
need to dial phone numbers directly as Operator Assistance won't be
available.
https://www.att.com/support/article/u-verse-voice/KM1511460/