If you want to assign a login profile to a location, you can click Manage → Locations in the left menu toolbar, double-click your location, move to the Settings tab, click Edit and change the Login Profile value from the drop-down menu.
Anyway, in some cases, you may want to assign the login profile to multiple locations, and you need a faster way to do the job.
A suitable solution for you is to click Manage → Login Profiles in the left menu toolbar, and click on Apply to () in the row corresponding to the login profile that you want to apply to your locations.
In the subsequent screen, just select your locations (in the Locations input field). If you enter an existing tag in the Filter by tags input field, then all the locations with that tag will be added.