To install licenses graphically using the License Administrator (hkey):

Navigate to the top right corner of the License Administrator to select the Login menu option.
Enter your email and password credentials for your SideFX license account.

To check for entitlements to install, navigate again to the top right corner to select the Entitlements menu option.

To install licenses using a non-graphical utility:

If you are running a headless system (a machine without a graphical display), please refer to to How do I Install licenses non-graphically?.