SOP-330023 An error occurred during the SOAP call. You don't have the required rights to view the detail
I am trying to send a SOAP call from Postman that goes to Adobe, this call is aimed towards subscribing a recipient to a service. The call looks like this:

I am also using these headers:
I am receiving a 'SOP-330023 An error occurred during the SOAP call. You don't have the required rights to view the detail.' message after firing: 
I am not sure why I am getting this message, I've made similar calls using this same endpoint and headers and have not had a problem until now.
Can anyone help? Please and thank you!
I've tried adding login credentials to the body but I keep getting the same message.