1 Your team administrator has to provide you IP of your gateway.
2 Open Azure and continue to Conditional access-> Named locations -> IP range location -> Set name of your GW + IP of yourGW /32 (f.e.: 188.8.131.52/32)
3 Mark as „Trusted location“ and continue with „Create“
4 You can see new Location now.
5 Open „Policies“ and click on „New Policy“.
6 Choose your New location in searchbar on the left side and specify who will have access.
7 Go back „Home“ -> Conditional Access and open „Clouds apps or actions“. Here you can set access restriction for all apps or choose Office 365.
8 Open Conditions (policy) -> Locations ->Choose your new Location and confirm with „select".