Setting up the Outlook Web add-in

The Outlook web add-in is a web client that runs inside the Outlook add-in panel. It can be side loaded from a local manifest file or added from your M365 integrated apps.

Side loading is a process that lets you add the add-in directly from a local copy of the manifest file. It may be blocked by your organization's M365 policies.

For either option, you will need a manifest file for your server.

1. Log in as a system administrator.
2. From the administration menu select System configuration > Settings > General > Client options.
3. Next to Get the Outlook OWA add-in manifest, press Download.

More information on adding applications to your organization’s add-in store, adding them to your Outlook, and side loading is available from Microsoft.

https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/add-ins-for-outlook/install-or-remove-outlook-add-ins

https://learn.microsoft.com/en-us/office/dev/add-ins/outlook/sideload-outlook-add-ins-for-testing

https://learn.microsoft.com/en-us/powershell/module/exchangepowershell/new-app?view=exchange-ps

https://learn.microsoft.com/en-us/office/dev/add-ins/outlook/outlook-add-ins-overview