Device Portal - Virtual Input to trigger Hololens

Hello,

I'd like to use a laptop's keyboard to trigger some behaviors on Hololens using Device Portal / Virtual Input.

I tried using this kind of code in Unity:

if (Input.GetKeyDown("f"))
{
// DoSomething()
}

It works fine when I debug the project using Holographic Remoting inside Unity: I just press F, and something happens.

But when I deploy the app on the Hololens, and send the keystroke using Device Portal / Virtual Input, the app doesn't recognize the keystroke: nothing happens.

Am I missing something in Unity?
Maybe I have to activate something in the app capabilities? (Edit/Player/Publishing)

Thanks