Error Message: Mismatch in redirect_uri.

I got the add on to show up in docs and I got the sidebar to pop up. But when I tried to connect to WordPress I got this error:


```
Invalid request, please go back and try again.
Error Code: invalid_request
Error Message: Mismatch in redirect_uri.
```

Please help :)
Josh

Start by reproducing the WordPress connection flow for the Google Docs add-on and compare the redirect URI sent by the add-on with the URI configured for the connection. The payload names no source files or tests, so locate the redirect and authentication entry points first; done means the connection no longer reports a redirect_uri mismatch.

Written by the indexing model from the issue text.