1. Click on "Manage Subscription". This can be found in the menu on the top-left of the home screen or under the "help" menu in the editor. 

2. Click on "Buy & Manage Subscriptions"

3. Click on "Buy More"

The following are the steps to assign users to the licenses:

1. Click on "Manage Subscription". This can be found in the menu on the top-left of the home screen or under the "help" menu in the editor.

2. Click on "Manage User"

3. Enter the email address of the user you would like to add and click the '+' button

4. Then click "Apply Changes"

Remember: You will need to open the link to the edition you originally purchased from.

The following are the links to the Manage Subscription pages:

Gantter for Google Drive    Gantter for G Suite or Google Drive        Gantter Cloud