Google has added back the edit code button to the Rich Results Test tool. Ryan Levering from Google posted this news on Mastodon saying, "Excited for this new button in Rich Results Test that makes it easier to test fixes to live code."
" I know a lot of people missed the Structured Data Testing Tool workflow for code editing and this brings a bit of it back," he added.
Here is a screenshot of the edit button, which you can find on the bottom right corner of the 
You can access this by plugging in a URL to the tool and clicking on "view tested page" in the interface.
Forum discussion at Mastodon.
