Apply a license to a user
Sign in to Office 365 with your Administrator account, or an account with Administrator rights assigned.
Click on the app launcher icon on the top corner left, and choose "Admin". This will launch you into the Tenant Admin Center.
On Office 365, choose Users > Active Users. Under users & groups, Choose Add Users, Reset password, and more.
Check the name of the user you would like to modify. On the right, under Assigned License, choose Edit:
In the Assign License Pane, select the license you want to assign. As example:
You can choose the product license by selecting the checkbox next to the available licenses.
To remove a license for the user, you can clear the check box against the license you would like to remove from the user.
Click the SAVE button at the top right of the screen.
If you have another user to assign the license to, you can now do it via the procedure above.