could someone who has the TouchBar tell me: is it possible to lock the function keys in place? Does the user or the app have ultimate control of its little scre

could someone who has the TouchBar tell me: is it possible to lock the function keys in place? Does the user or the app have ultimate control of its little screen? edit: I say this as someone who loves nyancat, and would love to have a nyan-mode on/off toggle somewhere, if I had a TouchBar.