Can we install/side-load outlook custom add-in for Mac programatically without manually installing

Is there a way to install outlook custom add-ins in Mac from terminal without requiring manually installation.From outlook documentation https://docs.microsoft.com/en-us/office/dev/add-ins/outlook/sideload-outlook-add-ins-for-testing we have to do it manually by selecting file from Get Add-ins --> My Add-ins ->Add from a file.

For example for word we copy manifest file in to a predefined location and that appears in my add-ins. Is there anything similar for Outlook?

Is there a way to install outlook custom add-ins in Mac from terminal without requiring manually installation.

Yes. From Microsoft Documentation:

Sideload Office Add-ins on iPad and Mac for testing

For side loading the add-on in Office for Mac, you need to save/copy the manifest file to the wef folder. If the folder doesn't exist, you must create it.

• Word: /Users/<username>/Library/Containers/com.microsoft.Word/Data/Documents/wef

• Excel: /Users/<username>/Library/Containers/com.microsoft.Excel/Data/Documents/wef

• PowerPoint: /Users/<username>/Library/Containers/com.microsoft.Powerpoint/Data/Documents/wef

The add-ins for Outlook are saved in a different way than add-ins for Word, Excel and PowerPoint. When you install a custom add-in from a manifest, the only thing actually installed is the manifest file, which is placed in a subfolder in:

/Users/<username>/Library/Containers/com.microsoft.Outlook/Data/Library/Application Support/Microsoft/Office/16.0/Wef/

The actual folder name depends on the installed version of Outlook. For example on my installation, the subfolder is named:

{7C3F43ED-AE0C-944A-A24C-7600FF485918}/5mwIVoCDw1ZTUJCywA2uyg==/Manifests/

The manifest.xml file is renamed to the value of the tag and the value of the tag inside the manifest - like this:

  <uuid>_<version>

For example if your manifest includes this:

<Id>EC13B9A0-5BA2-676A-956B-C583BDC94D5E</Id>
<Version>1.1</Version>

It would be named like this:

ec13b9a0-5ba2-676a-956b-c583bdc94d5e_1.1.0.0

Unfortunately just adding your file to the directory is not enough to fully install the add-in. The next time you open Outlook, the add-in will actually be installed and show up in the ribbon - but after a short while, Outlook will discover that it is not supposed to be there, and it removes the add-in again. Including deleting the file from the file system.

This indicates to me that the installation of the add-in is registered with Microsoft's servers - the same way as when you add an add-in from a URL.