To assign licenses to Salesforce users, follow the below steps:
- From Setup, enter Installed Packages in the Quick Find box, then select Installed Packages to find the installed package that has available licenses.
- Click the Manage Licenses link next to the Mass File Download name.
- Click "Add Users."
- Choose a view from the drop-down list, or click "Create New View" to build a new custom view.
- Click a letter to filter the users with a last name that corresponds with that letter, or click All to display all users who match the criteria of the current view.
- Select users.
- To select individual users, use the checkboxes. Selected users are listed in the Selected list. When the list includes all the users to whom you want to assign licenses, click Add.
- To select all users for the current view, click Add All Users, then click OK.