Show "Add content" for specific field when it is empty

Dear support team,
I have searched the support forum without any helpful hint.

User story:
An unregistered or logged-in user is watching an entry on the details page. Specific fields are shown regardless of being empty. Each of these specific fields provide a “Add content” link which opens the edit entry page (or sign in page for guest users). The user clicks on the link, is redirected to the edit form and updates the entry.

The goal:
Encourage users to add missing information, show where vital content is missing.

Goal achieved when:
– Show empty fields with “Empty” placeholder
– Show empty fields with “Add content” link to edit entry
– Show specific empty field with placeholder or link

Provided knowledge level:
– PHP function or hooks
– Shortcode customization
– CSS