How can i assign keys to trigger facial expressions whilst on Live Link?

Hi. I need help.

I have a wonderful UE4 model ready for live link on UE 4.27.

It works great but I find the expressions to be quite weak finding myself having to exagerate my expressions to get the model slightly close to what I want for this style of cartoon.

I would like to know if its possible (and steps) to assign three keyboard keys for three extreme expressions: Y for super happy, B for super sad and H for super angry.

I tried with Key>Play Animation and it does trigger a recorded expression but it also forces my model to “face camera” and spontaneously cuts off the live link from my iPhone. I want only to trigure the expression and keep the head movement the live link is sending.

Another lesser option would be to be able to change the sensitivity of UE4 to the live link? to exagerate so to speak the facial expressions I make?

please someone help happy to pay for your help.