Add-in can be installed directly into Outlook using this special Microsoft "sideloading" link: https://aka.ms/olksideload
Wait a second for the Add-ins dialog to show up, then go to My addins β Custom β Add Custom Add-in and upload the .xml
file provided to you by TonicDM.
After closing the Add-ins dialog box refresh the browser and the add-in will be available in the Apps list.