.. https://www.advancedcustomfields.com/resources/adding-fields-taxonomy-term/

add extra field
https://wordpress.stackexchange.com/questions/8736/add-custom-field-to-category
cr. https://wordpress.stackexchange.com/questions/255559/how-to-add-featured-image-for-category-without-a-plugin
.. https://en.bainternet.info/wordpress-category-extra-fields/
… https://yourblogcoach.com/how-to-add-taxonomy-images-in-wordpress/
… https://www.blogprocess.com/affect-an-image-to-categories-in-wordpress-without-plugin/