type something. it matches against what you type. Or you could turn on the contact pane on the left of the screen by pressing F9

I don't know if I'm explaining it right. I am using windows 11, Firefox version 143.0.3 (64-bit). After I click on the 'compose' tab in the menu, & the compose a new message screen appears with the cursor in the 'To:' area, I used to click or double click in that area and suggestions would appear below the 'To:' area. This same feature would work in the 'Cc:' area also. The suggestions seamed like they were from previous messages sent. It seams like this feature quit working around April of this year. Maybe I somehow turned it off or a Firefox update changed it. How can I get it to behave like that again? I tried the 'F9' key & it didn't help. I also tried typing the first letter of what I had typed before & that did not work either. Thank you for the help.