Worth mentioning…
You can use the Tools>Check Media menu option to scan your notes and media folder. It will generate a report of files in the media folder that are not used by any notes, and media referenced in notes but missing from your media folder. It does not scan question or answer templates, which is why you can’t place media references to fields in the template. If you need a static image or sound on every card, name it with a leading _ (e.g.,
\_dog.jpg) to tell Anki to ignore it when checking for media. If you delete media using the unused media check, Anki will move it into your operating system’s trash folder, so you can recover if you accidentally delete media that shouldn’t have been deleted.
Media - Anki Manual