Simply add a picture to a mp3

I’m totally beginner.

I just want to stick a picture to a mp3 (or other audio file format). My song and my image are not commercial. There are not “metadata” about them. Just a mp3 and a picture of mine.

Currently I can drag an audio file in the soft and add a picture in the square at the bottom right. but that’s all. I don’t know how to save.
The “save buton” on the top seam to change nothing when I clic on it.

My purpose is to use it in a hardware mp3 reader.

Can I do it with this soft and, if yes, how do I have to process?

best regard

Put an image cover.jpg in the folder.
In the settings under cover art you can enable a local files cover art source.
It should then pick up the local image asnd should import this.

Picard is designed to work with the musicbrainz database and works best if there is an entry in the database to pull tags from.
Other software may be better if you want to maintain your own tags.

You need to enable embedding images in Options > Cover Art and also enable “Save tags to files”.

If both are enabled the image should get saved to the file. The steps you describe are exactly how this is done.