If your Google Add-ons are not working as expected or if you are unable to install Google Docs add-ons from the Chrome store, it is likely that your GSuite (Google Apps) admin has disabled the setting that allows domain users to use add-ons.
Here’s how they can enable add-ons for your Google Account from the Google Apps admin dashboard.
Step 1 - Login to your Google Apps admin console at admin.google.com
Step 2 - Go to Apps -> Google Apps -> Drive and make sure the status is “ON” for everyone.
Step 3 - Go to Apps -> Google Apps -> Settings for Google Drive -> Data Access and enable the following settings.
Drive SDK (Allow users to install Google Drive apps) Google Drive apps allow users to open their files in web apps installed from the Chrome Web Store.
Add-Ons (Allow users to install Google Docs add-ons from add-ons store) Docs add-ons allow users to use Docs features built by other developers.
The Admin console setting for add-ons controls Docs, Sheets, and Forms; there are not separate settings for each document type.