1) If you are on the integrations page, click three dots on the Office add-in tab > Install Add-in.
2) Click Install Add-in.
3) On the Microsoft AppSource page that opens click Get it now.
4) On the next page, select Everyone, Specific users/groups, or Just me to specify who the add-in is deployed to. Use the Search box to find specific users or groups. If you've deployed to just yourself, you can select Change who has access to add-in to deploy to more users later. Please, note that only users with installed Add-in will have signatures applied to emails after they are deployed.
5) Read the app permissions and click Next to proceed.
6) Click Finish Deployment.
7) Click Done.
A green tick appears when the add-in is deployed.
Please Note! Outlook add-ins can take up to 24 hours to be processed by Microsoft 365 and users might need to relaunch the Outlook app.
The minimum required version for Outlook desktop:
For Outlook on Mac is 16.54 (21101001), New Outlook mode.
For Outlook on Windows is 16.0.14511.10000.