Power Query Web API with Session Key

Hello,

I am trying to connect Power BI to our ticketing system API to get ticketing data for a Power BI report.  I am using Power Query Advanced Editor to write the code to connect to the API POST.

Here is my code to connect to the API:

I have used the API Reference guide to build this code just like their examples and I keep getting either two errors. 

First error: 

When I set Cookie equal to sessionKey={created api key}

Second error:

I thought the API didn't like the text "sessionKey" in the header so I took it out and changed it to this:

and get this error

I have tried multiple modifications and cannot get it to work.  I am using Anonymous access currently.  I tried using Web API access and get this error when I enter in the API Key.

Any help would be appreciated.

Thanks,

Tim