When STAAD Foundation Advanced is launched, the application will present a message dialog that will report which license will be used in the session:
Make sure to select the correct license and then apply it by clicking the OK button.
If the License Configuration window does not appear at startup, click the "License Configuration" button from the application settings:
Note that it is possible to use STAAD Foundation Advanced when not connected to the Internet by arranging to have a license reserved. More details can be found here.