You are not authorized to use transaction ACO_PROXY

For an integration scenario I had to develop ABAP code in SAP BTP ABAP Environment (Steampunk) that calls a function module in the customer namespace (say YTESTRFC) in an on premise system landsacpe (D-, Q, P-).

Since the types being used are only available in that backend system landscape I wanted to use transaction ACO_PROXY to generate an XML file that can be used to generate a service consumption model in Steampunk

Unfortunately there was no role available in the development backend system that contained the value ACO_PROXY for the authorization object S_TCODE.

So what can I do?