Google tasks position error

I am trying to use the google tasks api in a chrome extension, but when I try too make a task with ?previous set I get this:

"{
 "error": {
  "errors": [
    {
    "domain": "global",
    "reason": "invalid",
    "message": "Invalid Credentials",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Invalid Credentials"
 }
}
"

This is the ur开发者_运维百科l I am using: 'https://www.googleapis.com/tasks/v1/lists/@default/tasks?previous='+lastid. I use javascript as my main language. I am willing to give code samples but only if necessary.

Try using oauth.sendSignedRequest like in the official google tasks api chrome extension, you should be able to add the previous argument in req['parameters'].