In your Google Admin Console settings, under Apps > Google Workspace Marketplace apps > Settings, you can select "Allow users to install any app from Google Workspace Marketplace" to allow users to install Comeen Workplace themselves.
A second and more secure option is to choose "Allow users to install only allowed applications from Google Workspace Marketplace", but you will need to add our app to your allowlist.
To do so, on your Google Admin console, go to Apps > Google Workspace Marketplace apps > Apps list:
On this page, click on "ALLOWLIST APP":
Type Comeen in the search bar and click on "Select" next to Comeen Workplace :
Click on "Allow users to install this app" then on CONTINUE
Authorize it for everyone or specific group(s) / Organizational Unit(s) and click on FINISH
Our add-on Comeen Workplace has been added to your list of authorized applications.
Repeat the operation for Comeen Workplace for Google Chat.