Microsoft Office 365 Add-ins are disabled for security purposes. If you click Get Add-ins in Word, Excel, PowerPoint, OneNote or Publisher, you'll get a message saying "Sorry, Office Office Microsoft 365 has been configured to prevent individual acquisition of Office Microsoft 365 Add-ins."
Outlook may allow you to install Add-ins, but you may be prompted to sign into those vendors' services or won't be able to access them at all.
...