I am using playroom on my mother's laptop because mine is unavailable currently. When I start the game and press f6, nothing happens. Note that to disable some of the default system actions mapped to the function keys, I need to press fn so that I can use the meaning the current program gives to them. Only the key to make the speech slower seems to work. How can I solve this problem?

I never had had a laptop where system functions had priority above function keys, so I can't help you, sorry.

That's a parameter of the system, you should have a look in the control panel to change that.