facilitatorAccessToken to verify transaction details (PERMISSION_DENIED)

Brand new to PayPal, tinkering with sandbox. My test orders are going through OK.

I would like to verify orders from my server and handle the provisioning tasks in the background for successful orders.

onApprove: function(data, actions) {
// data has things that are of interest, see below.
....
}

data has :

{
  "orderID": "4P1187891ORDERID",
  "payerID": "4MEHE6UPAYERID",
  "paymentID": null,
  "billingToken": null,
  "facilitatorAccessToken": "aHR0cHM6Ly9hcGkuc2FFACILITATORACCESSTOKENtL3YyL2NoZWNrb3V0L29yZGVycy80UDExODc4"
}

Their doc says this is how i can get the transaction details:

curl -v -X GET https://api.sandbox.paypal.com/v2/checkout/orders/5O190127TN364715T \
-H "Content-Type: application/json" \
-H "Authorization: Bearer Access-Token"

So I carve my curl command as:

curl -v -X GET https://api.sandbox.paypal.com/v2/checkout/orders/4P1187891ORDERID \
-H "Content-Type: application/json" \
-H "Authorization: Bearer aHR0cHM6Ly9hcGkuc2FFACILITATORACCESSTOKENtL3YyL2NoZWNrb3V0L29yZGVycy80UDExODc4"

I use the facilitatorAccessToken as the Access-Token in curl above, and it is failing as:

{"name":"NOT_AUTHORIZED","details":[{"issue":"PERMISSION_DENIED","description":"You do not have permission to access or perform operations on this resource."}],"message":"Authorization failed due to insufficient permissions.","debug_id":"420XXXXX03","links":[{"href":"https://developer.paypal.com/docs/api/orders/v2/#error-PERMISSION_DENIED","rel":"information_link"}]}  

Has anyone suffered this before? I am assuming facilitatorAccessToken can be used as Access-Token to get Transaction Details - is this not the case?