Roadtrek Sewage Discharge Manual Cleanout - Connector

Sorry, I was not clear - not interested in connecting to the macerator pump or the 1 inch dump hose. I'm interested in a installing a connector to the manual clean out on the Roadtrek. It is a 3 inch pipe clean out, with a screw out plug.

The idea is to attached a connector permanently with a plug to allow no seepage. Then when I need to dump out when the macerator pump isn't working, I could quick connect a 3 inch hose to this new connector.