matheweis

You may want to try using a favicon plugin. There are several good ones available here:
https://ww.wp.xz.cn/plugins/favicon-by-realfavicongenerator/
https://ww.wp.xz.cn/plugins/favhero-favicon-generator/
https://ww.wp.xz.cn/plugins/quick-favicon/

… or if you want to make your own favicon, you could use one of these sites:
https://iconverticons.com/online/
https://realfavicongenerator.net/favicon_compatibility/