How can I hide the vertical side bar tabs menu?

Hello,

To collapse the vertical side tabs menu in firefox, press Cmd + Option + Z to toggle vertical tabs on and off. Alternatively, you can also click the cog icon on the sidebar and toggle it off.

If you want to adjust auto hide preferences, go to menu > settings > general > tabs, then look for Sidebar or Vertical Tabs and adjust hiding preferences accordingly.

Thanks a lot. The cog icon adjustment does seems to do the job. But just for your info : Cmd + Option (alt) + Z does something odd - a new black sub window appears at the bottom of the page to do with Inspector / Console / + other things ; my Settings does not seem to have any of the sub options you mention (I had tried this one before).

Can I ask something else. I need to change my primary Mozilla email address - I can get it to send me a confirmation code to get at my personal info page but on that page it wont let me make any change to that one piece of info. Any ideas?