No, the problem is not in the return url.
The problems are:
- You're sending the URL to
https://api.twitter.com/
without any further URI to indicate the service that you're requesting. Since you are passing an oauth_callback, it's likely that you wanted to accesshttps://api.twitter.com/oauth/request_token
- You can't pass an
oauth_callback
tooauth/request_token
using aGET
request: you need to use aPOST
request instead.
Hopefully that explains for you what's wrong with this URL.
If you are having more problems accessing the Twitter oauth API, I suggest that you read this primer from Twitter on how to use this API: