Shutdown/eset pram when Mac is hung

to do an emergency power off when you are hopelessly stuck:

Press and hold the power button until your Mac powers down. This could easily take ten seconds of pressing.

On models with TouchBar, the home position (where the fingerprint reader sits) acts as the power button for this purpose.

Hi,

Hold down the power button for about 10 seconds until it shuts down, then you can boot up normally or reset NVRAM or whatever you'd like to do.