Thank you for your response and your effort! I do understand that my followup question is not related to the plugin, but maybe you know an easy solution to my request that could help me and other users seeing this thread:
I am looking for a bash command, that would add the same exif information to all files in a directory. In mycase, that would solve the problem. Something like:
writeexif “copyright_author = author name” “somewhere/pictures/*.jpg”
I am having full access on debian 10 server.