When Bria is launched for the first time it asks for the license key. Usually that license key is stored locally and is verified on each launch afterwards. If you find that Bria is asking for a license key every time it is launched, then it's likely that Bria is having difficulties either saving or accessing its license key file.
First try launching Bria by right clicking on its shortcut and choosing "Run as administrator". This gives Bria temporary admin rights that should allow it to save its key locally. It should only be necessary to run Bria with admin rights once to let the license key get saved locally, afterwards you should be able to run Bria normally.
If that doesn't help, check to make sure there is nothing on the system that could block Bria's access to the folder where it stores its license key, which is C:\ProgramData\CounterPath Corporation\Bria\5.0
If Bria is still asking for the license key on each startup please open a ticket with our support team.