Edit: Code error on my side! Wasn't authenticating.
I don't think this is a permissions issue or incorrect API key/secret as I can use other endpoints without issue, and permissions have been checked. If I modify the markAsShipped function to spit out JSON of the form_params
array instead and the copy that to a Postman POST call, it works fine.
$orderService->markAsShipped(12907921, "other", "2020-12-01", "TrAcKiNg", false, true);
results in
Client error: POST https://ssapi.shipstation.com/orders/markasshipped
resulted in a 401 Unauthorized
response:
401 Unauthorized