At the moment, only Administrator can code an image into the title bar of a post as shown on your demo page https://demo.themegrill.com/masonic/ 1) How can I add other roles, such as Author to do this too. Where do I change this in the code? 2) What is the image size used in header posts?
Hi @ict1.ris Allowing other users with Author role to edit customizer needs lots of code customization. If you really want this feature, you can contact our customization team. https://themegrill.com/customization/
Or, you can simply search for a plugin that provides such functionality in WordPress Plugin Repository. We’ve used 1350 x 500 px image on our demo. You can use an image with similar size.