This is my first time using LibreOffice. I created a document in Writer but cannot save it no matter what method I use. What's wrong?

I’m using LibreOffice 7.0.6 with Mac OS 10.15.7.

Hi. New security settings in MacOS.

You need to give LibreOffice full disk access from System Preferences > Security & Privacy. See this site on how to do it if you aren’t sure: Explained: What is Full Disk Access & Full Permissions on macOS Mojave .