Below is a suggestion on how to set-up Microsoft Teams Calling Policies to work with the @voice platform. You can customise calling policies differently to meet your end customers requirement, however the labels highlighted is required to be in that specific setting or calls may not be able to connect.
Terminology for the labels can be found on Microsoft's guide - https://docs.microsoft.com/en-us/microsoftteams/teams-calling-policy
Make Private Calls - On
Call forwarding and simultaneous ringing to people in your organisation - On
Call forwarding and simultaneous ringing to external phone numbers - On
Voicemail is available for routing inbound calls - User controlled
Inbound calls can be routed to call groups - On
Allow delegation for inbound and outbound calls - On
Prevent toll bypass and send calls through the PSTN - Off
Busy on busy is available when in a call - Off
Allow web PSTN calling - On