1: the Reading Pane add-in
In the Microsoft 365 admin portal navigate to the Integrated Apps section.
Click the Upload custom apps button.
Choose Office Add-in as the App Type, and https://app.tonicdm.com/outlook/r1.xml as the link to the manifest file.
Click Validate, then Next.
Choose whether to deploy to the Entire organization or only to Specific users/groups.
After accepting the permissions and confirming the deployment, it usually takes 1-3 days for the add-in to appear in Outlook.
2. the Compose Pane add-in
Return to the Upload custom apps button.
Choose Office Add-in at the App Type, and this time use a different link to the manifest file:  https://app.tonicdm.com/outlook/c1.xml 
Click Validate, then Next.
Choose whether to deploy to the Entire organization or only to Specific users/groups.
Conclusion
After completing these steps:
- There is a delay of between 12 hours and 3 days before staff will see the add-ins in their Outlook. 
- Each version of Outlook shows the TonicDM icon in a different place. - Reading Pane: Sometimes it is on the right side of the Home ribbon next to the "Viva" button; sometimes it is in the top right of the message near the Reply and Forward icons, or inside a  icon. icon.
- Compose Pane: The TonicDM icon is on the right side of the Message ribbon. 
 





