How user uses the key (linux terminal)

Hi.Sorry for a noob question. But I am a little bit confused on how to use TurboActive,from the user perspective. So I, as product owner,have created a key for the user single license.On the software side I integrate your API,based on the C example.That's fine. But my product has no GUI,this is C++ app which is run via terminal. How my user is supposed to enter his license key for activation? Thanks.

It's up to you. You could, for instance, make a simple commandline switch for your app in which they provide the product key to activate. This is what the TurboFloat Server does (it has no GUI):

https://wyday.com/limelm/help/turbofloat-server-commandline/

Wow,that was easy )) Thanks. Looks like I am gonna go with this product.