Did they by chance try running OS upgrade from Ubuntu 22 to 24? Need a lot more info to help, check their previous commands to see what exactly they were running.
Try manually switch the control panel server to apache:
appcd-cli 127.0.0.1 change-webserver apache
PS, why are you letting some random bums off the street run updates on your servers? Really bad idea to be hiring sysadmins from Fiverr lol
