how to get bookmarks restored from older version of firefox

Yeah, you may be able to get them back. First, I’d check '''Bookmarks → Manage Bookmarks → Import and Backup → Restore''' and see if Firefox has an older dated backup. Pick one from before the bookmarks disappeared. Just be aware that restoring it replaces the bookmarks you have now. If this happened after an update, check your desktop for an '''Old Firefox Data '''folder. Firefox sometimes leaves the old profile there, including older bookmark backups in the '''bookmarkbackups''' folder. I’d make a copy of whatever you find before changing anything. Better to have a backup than accidentally make the damn problem worse.