Add accept option to image blueprint and assign this template to cover field

site/blueprints/files/image.yml

@@ -6,6 +6,10 @@ title: Image
 # In addition to the fields defined in this example blueprint, you can also set what type of file is acceptable
 # when this blueprint is used, which allows you to control what users can upload.
 # More about file blueprints: https://getkirby.com/docs/reference/panel/blueprints/file
+
+accept: 
+  type: image
+
 columns:
   - width: 1/2
     sections:

site/blueprints/pages/album.yml

@@ -27,6 +27,9 @@ columns:
       cover:
         type: files
         multiple: false
+        query: page.images
+        uploads:
+          template: image  
       headline:
         type: text
         placeholder: "{{ page.title }}"