Cannot Authorize Google in SSH Session

I've followed the steps from #975 but the issue I'm having is that pasting the code generated from my browser into the SSH window does nothing. It's not accepting input after saying "Follow the instructions on the page."

• Your vdirsyncer version: 0.19.1
• If applicable, which server software (and which version) you're using
• Your Python version: 3.8
• Your operating system: Ubuntu 20.04
• Your config file: Basic Google/Nextcloud that's been working for years
• Use vdirsyncer -vdebug for debug output. The output is sensitive, but
  please attach at least the last few lines before the error (if applicable),
  censored as necessary. This is almost always the most useful information.

This is where I'm stuck:

Opening https://accounts.google.com/o/oauth2/v2/auth?response_type=code&client_id=999999999999-vqa6roj8c0kbnvu4fv0mdu92bt4qjgl5.apps.googleusercontent.com&redirect_uri=http%3A%2F%2F127.0.0.1%3A52447&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fcalendar&state=MMtv8oFuXcCmGGc5quGOrPGmbJRsdt&access_type=offline&approval_prompt=force ...
warning: No graphical browser found. Please open the URL manually.
Follow the instructions on the page.

I paste the code where the cursor is in the SSH window and hit enter, nothing happens and prompt doesn't move to next steps.

Reproduce the Google authorization flow from an SSH session with vdirsyncer 0.19.1 on Ubuntu 20.04, following issue #975 and capturing the final lines from -vdebug. Trace the authorization prompt and input handling; done means the pasted browser code is accepted and the next authorization steps proceed.