INT Token Endpoint - error grant_type is missing

I am in the process of completing our development of the new CIS2 authentication with eRS and am currently on step 5:

Sending the expected payload however is throwing an error and I’m unable to determine what is wrong as the grant_type is included:

(values modified for security)
curl --location --request POST ‘[OUR_APP_ID]&client_secret=[OUR_APP_SECRET]&redirect_uri=[OUR_URL]&grant_type=123&code=123
–header ‘Content-Type: application/x-www-form-urlencoded’

However the response I get back is:
“error”: “invalid_request”,
“error_description”: “grant_type is missing”,
“message_id”: “rrt-6783935314234691558-c-geu2-22818-486135-1”

Does anybody have any advise on this endpoint? I’m declaring the grant_type so not sure how to resolve this?

I believe this has been resolved due to the message payload being sent back not correctly registering the content-type as url-encoded.