Trunk Auth (401) Help

Hello Experts

I have a FreePBX system running version 12 of FreePBX with Asterisk 11.17. The system currently has two (2) SIPSTATION trunks and is working as expected. We have requested a 10 channel SIP trunk from the internet provider as part of the access plan. The provider has set up the trunk and I can get the trunk registered. The issue is, when a call comes in they are seeing a 401 error, i.e. the incoming call is trying to authenticate. I have tried every combination of peer and SIP settings and still cannot get the inbound calls to work.

Is there some setting that I’m missing that would cause the system to require authentication from the trunk (peer)? I did enable “allow anonymous inbound sip calls” as a test but the provider is still seeing the 401 error.

Any and all help much appreciated!