Hi @jja ,
I'm sorry for providing a wrong answer earlier, please try the following steps if it meets your needs:
1. Log into the admin center as a global administrator here .

2. Click ‘Add a custom tile’.
Enter the details for the new tile in the app menu.

3. Your new menu tile will appear in the list.

4. You will need to instruct users on how to Pin the app to the primary menu for quick access.

5. Once Pinned the application will display whenever the user clicks the main app menu!

Best Regards,
Charlie Choi