How can I remove a retweet from a user who has blocked me via the Twitter API?

I'm using the POST method on the following API call:

I've set Authorization Type to OAuth 1.0 and "Add params to header".

How can I get my Consumer Key, Consumer Secret, Token and Token Secret for my user account?

I added my phone number and tried creating an App at, using those keys to send the request.

But I still get this error when sending the request:

    "errors": [
            "code": 32,
            "message": "Could not authenticate you."

What am I doing wrong?