You can use "Always Show" (toggle via Ctrl+B).

Make sure toolbars like the "Bookmarks Toolbar" are visible. Open the Customize page and set what toolbars (Show/Hide Toolbars) and toolbar items to display.

• Right-click empty toolbar area => Customize
• "3-bar" menu button => Customize
• View -> Toolbars
  *you can tap the Alt key or press the F10 key to show the hidden Menu Bar temporarily

• check that "Bookmarks Toolbar Items" is on the Bookmarks Toolbar
• if "Bookmarks Toolbar Items" is not on the Bookmarks Toolbar, drag it back from the Customize palette to the Customize page to the Bookmarks Toolbar

• if missing items are in the Customize palette, drag them back from the Customize page to the toolbar
• if you do not see an item on a toolbar and in the Customize palette, click Restore Defaults in the Customize palette window to restore the default toolbar set.

• https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars

You can check for problems with the places.sqlite and favicons.sqlite files in the Firefox profile folder.

• use the "Places Database" -> "Verify Integrity" button on the "Help -> More Troubleshooting Information" (about:support)

If errors are reported with "Verify Integrity", close and restart Firefox or reboot and retry.

thanks, this is correct. "Make sure toolbars like the "Bookmarks Toolbar" are visible."