Not authorized to Run Response Plays

I end up getting this error --------

 |  … $response = Invoke-RestMethod -Uri $URL -Method POST -Headers $header …
 |                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 | {"error":"Not authorized to run response plays"}

When using the Response Play API below. I am a bit confused as to why this is failing because my APIAccessKey works with the other endpoints? Any help would be greatly appreciated form Support or the Development community.

$URL = 'https://api.pagerduty.com/response_plays/ResponsePlayJsonID/run'

function Start-ResponsePlay {
            $headers=@{}
            $headers.Add("Content-Type", "application/json")
            $headers.Add("Accept", "application/vnd.pagerduty+json;version=2")
            $headers.Add("From", "me.com")
            $headers.Add("Authorization", "Token token=APIAccessKey")
            $response = Invoke-RestMethod -Uri $URL -Method POST -Headers $headers -ContentType 'application/json' -Body '{
                    "incident": {
                    "id": "Random",
                    "type": "incident_reference"
                    }
            }'
            return $response
        }
        Start-ResponsePlay

Just a quick question - when you log into PD, are you able to run the same response play via the PD UI or Mobile App?