Hey @Giorgio-Chiodi -- the hosted service does not provide administrators with the ability to directly access their server/instance, which is part of how we can maintain stability on our platform.
You can grant us access to a theme you created (if it is on npm), and we can install it for you, but we cannot ensure compatibility with them
When the imgur plugin is enabled, you can upload images just fine. When it isn't - image uploading is disabled.
Is that intended? I enabled file uploads and file uploads works fine, icon shows up, etc.