You can use ArcGIS for Teams to bring maps and location intelligence into Microsoft Teams. With ArcGIS for Teams embedded in Microsoft Teams, you can quickly and seamlessly bring ArcGIS content into a chat or meeting.
Use ArcGIS for Teams to search for public ArcGIS Online content. When you sign in to your ArcGIS Online or ArcGIS Enterprise account, you can search for your or your organization's private content, including maps, scenes, layers, files, apps, stories, and so on.
There are two ways to install ArcGIS for Teams. You can install directly from the Microsoft App store to a personal (private) scope or to a selected team, chat, or meeting channel, or you can install ArcGIS for Teams from within an active chat, team, or meeting, provided that you have the necessary channel member privileges.
You can also add ArcGIS Maps (ArcGIS for Teams) 
to your Microsoft Teams toolbar for quick access.
Sign in to ArcGIS
After installing ArcGIS for Teams, you can use the app to search for public ArcGIS content. Use ArcGIS for Teams anonymously or sign in to your ArcGIS Online or ArcGIS Enterprise account to access content and information from your organization.
To sign in to your ArcGIS account, click Sign in at the welcome message prompt. You can also sign in or out in the search window at any time.
Sign out
To sign out, go to the Options tab in the private scope installation and click the ArcGIS sign out button. If you are signed in to ArcGIS or any related apps from Esri in your browser, signing out in ArcGIS for Teams does not sign you out in your browser.
Search for items
Use the search tool to search ArcGIS content. Type keywords or phrases to @ArcGIS Maps in the chat message text box to find relevant maps, scenes, files, layers, and apps.
View items
Open maps, scenes, files, layers, and compatible apps on the Viewer tab in the private scope installation to view and edit them in Microsoft Teams. You can also use the Open in browser option.
Note:
To view content in ArcGIS for Teams, turn off Disable GPU hardware acceleration in the Microsoft Teams settings.
Share items
Use @mentions to quickly find and share ArcGIS content in chats and channels. Type @ArcGIS Maps in the message or search text box to search for the content you want to share and send it in a message.