A problem with the scripting tutorial

Trying to add visual studio to unity to open scripts and edit them is impossible. I can't find a way to add or even check if video studio is used as my default external script editor in unity, because Edit: Preferences: External Tools doesn't even exist as a drop down menu option. I hit edit, but preferences doesn't show.
When I try to open a script in my projects it just opens with a regular text file. Even though visual studio is installed and updated fully on my pc.

What can I do and why is edit: preferences not showing at all for me?

I'm on a 2020 27 inch iMac. Everything is fully updated.

 

Sorted. Sorry people but I know can't for the life of me find out how to remove this post.

 

You can't remove a post. What you should do instead is post the fix that you found, so the next poor sap who stumbles across your post searching for answers may have an easier time.

 

Agreed. But it wasn't really a problem once I'd worked it out. You see, It really came down to my inability to adapt. I'm not accustomed to using apple software, so the idea that 'preferences > external tools' might be found under the drop down menu headed "Unity' instead of 'Edit' alluded me. Took me over an hour to work this one out. God help me, but still, onto the next problem!