Explanation
you should configure an emergency calling policy to define what happens when a Teams user in your organization makes an emergency call. You can set who to notify and how they are notified when a user who is assigned the policy calls emergency services. For example, you can configure policy settings to automatically notify your organization's main receptionist and have them listen in emergency calls.
To create a custom emergency calling policy, you can follow these steps1:
In the left navigation of the Microsoft Teams admin center, go to Voice > Emergency policies, and then click the Calling policies tab.
Click Add.
Enter a name and description for the policy.
Set how you want to notify people in your organization, typically the main receptionist, when an emergency call is made. To do this, under Notification mode, select one of the following:
Send notification only: A Teams chat message is sent to the users and groups that you specify.
Conferenced in but are muted: A Teams chat message is sent to the users and groups that you specify and they can listen (but not participate) in the conversation between the caller and the PSAP operator.
Conferenced in and are unmuted: A Teams chat message is sent to the users and groups that you specify and they can unmute to listen and participate in the conversation between the caller and the PSAP operator.
Set the Emergency service disclaimer to show a banner to remind your end users to confirm their emergency location.

Reference:
https://docs.microsoft.com/en-us/microsoftteams/manage-discovery-of-private-teams#set-whether-existingprivate-teams-are-discoverable

Reference:
https://docs.microsoft.com/en-us/microsoftteams/migration-interop-guidance-for-teams-with-skype

Explanation
Graphical user interface, text, application Description automatically generated

Reference:
https://docs.microsoft.com/en-us/microsoftteams/teams-app-setup-policies#assign-a-custom-app-setup-policy-to-
https://docs.microsoft.com/en-us/powershell/module/skype/grant-csteamsappsetuppolicy?view=skype-ps

Reference:
https://docs.microsoft.com/en-us/microsoftteams/teams-live-events/set-up-for-teams-live-events