To add a location to Teams:
Click Add a location.
Choose a name for your location.
You may not need the IPv4 address field if:
The location you're adding only uses IPv6
Users will be sending all DNS requests from this location using DNS over HTTPS via a browser
If any of the above apply to your case, click Delete to the right of the IPv4 field.
Select any policies you want to apply to this location.
If you'd like to set this location as default, check the Set as a Default Location checkbox.
Click Add location.
This will show you your location's details, and instructions on how to change DNS resolvers on your router, browser, or OS.
Your location is now listed under Gateway > Locations.