Rally toPower-bi connection

I am trying to connect User stories from Rally to Power-bi as a data source using Rally API. Here is the query that i am trying to execute. The query runs fine but unfortunately it returns a blank dataset. 
Query: 

=Json.Document(Web.Contents("https://rally1.rallydev.com/slm/webservice/v2.0/requirement?query=(CreationDate%20%3C%20%E2%80%9Ctoday%20%E2%80%93%20365%E2%80%9D)&&project=https://rally1.rallydev.com/slm/webservice/v2.0/project/projectid&fetch=CreationDate&projectScopeUp=false&projectScopeDown=false&pagesize=15&start=1&order=CreationDate", [Headers=[#"ZSESSIONID"="rally API key "]]))

Experts, please help me solve this. Thanks in advance:)