Resolving the 'Error creating plugin' issue when adding Google OAuth to your application

I’m trying to add Google OAuth to my application but I’m getting the error

{"detail":"Error creating plugin: {\"message\":\"'openai'\"}"}

when OpenAI is trying to find my manifest file.
Previously, I got errors indicating various pieces of information in the manifest are missing, but when the auth object looks like this

   "auth": {
      "type": "oauth",
      "client_url": "{DOMAIN}/oauth",
      "authorization_url": "{DOMAIN}/auth/oauth_exchange",
      "scope": "",
      "authorization_content_type": "application/json",
      "verification_tokens": {
        "openai": "Replace_this_string_with_the_verification_token_generated_in_the_ChatGPT_UI"

I get the error previously stated.

You can see a full working repro of my app on my github feargswalsh92/planPen (can’t include links here)