How to add add-ins to Exchange Online?

Step 1: Sign into Exchange admin center.

Step 2: On the left pane, click More Features

Step 3: On the left pane, click on organization and select add-ins tab

Step 4: Click Add icon on the top-left

Step 5: Select App from app source

Step 6: Search for the add-in in App source

Step 7: Click Get it now