In order for Indigo users to have the ability to use Indigo Mobile, you need to assign the users with the basic (required) permission sets. You can then assign the optional permission sets to provide users with extra Indigo Mobile functionalities. 

To assign the required or optional permission sets to Indigo users:

1. In the left sidebar of Indigo, click on Administration.

2. In the Main section, click on Users. 

3. Double-click on the user for whom you want to assign Indigo Mobile permissions.

4. Click on Insert (plus icon) in the functions bar.

5. Under User Permissions Sets, search for and select the permission sets you want to give to the user.

6. Click Save.

When you have assigned Indigo Mobile permissions to the user, you can invite them to download and use the app.