The "Edit This Bookmark" dialog that opens if you click the highlighted star has a checkbox with "Show editor when saving" (shortcut key in the dialog is Alt+S). This item is at the bottom just above "Remove Bookmark" and "Done". You can click the highlighted star a second time to open the "Edit This Bookmark" dialog.

See "How do I change the name or location of a bookmark?"

• https://support.mozilla.org/en-US/kb/bookmarks-firefox

Thank you. I didn't see any highlighted star when I clicked on "Bookmarks" at the very top of the screen. Now that I understand the star is in the URL bar, I should be able to manage.