The Better Categories Images Plugin allow you to add image with any category or taxonomy.
Use:
+ $thumbnail_id = get_term_meta( $term_id, 'thumbnail_id', true ); \\ [get_term_meta](https://developer.wordpress.org/reference/functions/get_term_meta/)
+ $image = wp_get_attachment_image( $thumbnail_id, 'full' ); \\ [wp_get_attachment_image](https://developer.wordpress.org/reference/functions/wp_get_attachment_image/)
better-categories-images
folder to the /wp-content/plugins/
directory