How to use shortcut and automation to create auto text reply when focus “out of office”

My niece found instructions for using shortcuts and automation to have an automatic reply to all text messages (not just contacts) when focus is set to an added “out of office” condition. I can’t find those instructions and everything I try is not working. Anybody had success with this. And WHY hasn’t Apple made this available already? I know we have been struggling with this for years and it makes it hard to use Apple as a work phone and go on vacation!