UI Enhancement Suggestion - Try It Panel - Link to subscription page for APIs that require a key

If there's space, it would be nice to have a small link to the subscription page after you click "Try it >" where the Subscription Key goes. So as a new developer, you're prompted to sign up if you want to trial the endpoint that requires a key
Ideally in a little (i) icon next to the Subscription Key box.

Start by locating the Try it panel and the Subscription Key field shown in the attached screenshot. Check how APIs requiring a key are identified and where the subscription page URL is configured. Done means the panel shows a small subscription link or information icon for key-requiring APIs and lets a new developer reach the subscription page.

Written by the indexing model from the issue text.