URL To Featured Image
by François-Régis Ferry on WordPress.org

URL To Featured Image field in the Gutenberg editor.
URL To Featured Image allows you to use an image hosted anywhere on the internet as the featured image (post thumbnail) for any post, page, or custom post type.
Perfect for:
– Using CDN-hosted images as thumbnails.
– Saving server space by not uploading large images.
– Dynamically updating featured images from an external source.
Key Features:
– Simple URL field in the post editor.
– Works with posts, pages, and custom post types.
– No extra database tables.
– Fully compatible with WordPress themes and loops.
– Uses standard WordPress functions like the_post_thumbnail().
– Ability to save the target image n the media libary if needed
How it works:
When displaying the post, the plugin replaces the default WordPress featured image with the one provided via the URL.
Custom Hooks
Filters
- 
friss_utfi_post_type_exclusions
Filters the post types where the URL To Featured Image metabox should not appear.
Parameters:- (array) $exclusions_list List of post types where the metabox is excluded.
 - (object)   $post          Current post.
Return: (array) Modified exclusions list. 
 - 
friss_utfi_url_allowed
Filters whether an external image URL is allowed before fetching.
Parameters:- (bool) $authorization Whether the URL is allowed.
 - (string) $url The external image URL.
 - (array) $parts            Parsed URL parts (from 
wp_parse_url).
Return: (bool) True to allow, false to block. 
 - 
friss_utfi_allowed_mime_types
Filters the allowed MIME types for external images.
Parameters:- (array) $mime_types       Allowed MIME types.
Return: (array) Modified list of MIME types. 
 - (array) $mime_types       Allowed MIME types.
 - 
friss_utfi_max_image_size
Filters the maximum allowed image size when fetching external images.
Parameters:- (int) $size               Max file size in bytes.
Return: (int) Modified maximum size. 
 - (int) $size               Max file size in bytes.
 - 
friss_utfi_image_data
Filters the raw image data fetched from the external URL.
Parameters:- (string) $image_data Raw image data (string).
 - (int)    $post_id         Current post ID.
Return: (string) Modified image data. 
 - 
friss_utfi_external_featured_image_alt
Filters the alt text for the external featured image.
Parameters:- (string) $alt_text The alt text (default: post title).
 - (int)    $post_id         Current post ID.
Return: (string) Modified alt text. 
 - 
friss_utfi_external_featured_image_styles
Filters the inline CSS styles applied to the external featured image.
By default, the plugin enforces responsive behavior (max-width:100%; height:auto;).
Parameters:- (string) $default_styles The default style string.
 - (int)    $post_id         Current post ID.
Return: (string) Modified CSS styles.