You can set or update a featured link on a topic by using the rails console.
From your server, enter the rails console from your Discourse folder:
./launcher enter app rails c
You can then use the @nathankershaw’s form to generate your command:
Topic.where(id: =topic_id=).update(featured_link: "=featured_link=")
Copy-paste the generated command inside your rails console and press Enter. It will set or update the featured link accordingly.
Example of the raw syntax for the command:
Topic.where(id: 9999).update(featured_link: "https://blog.discourse.org/")