To assign a field rep a license, click on field reps found on the left side of the screen under USERS.
To select the field rep, click on the name found on the right side of the screen as shown below.
On this screen, click on edit on the top right of your page.
To assign a license to select the license by clicking on the drop-down box shown below. Select the available license as show below.
Be sure to save your changes by clicking on SAVE on the top right of the screen.