Welcome to the forum, Loranimal.
The A194HW has a cassette potty. Likely its a Thetford. The cassette tank that pulls out of the enclosure to be taken to a toilet or dump station for emptying. I've had these in the past, and it is a clean and easy way to dispose of the waste. I kept a box of disposable gloves stowed in the cabinet for extra assurance while servicing and handling the blue liquid chemicals.
The shower drain is just below and to the right of the door to the cassette on the entrance side of the camper. It does not connect to the sink drain. If you'll notice, the sink outlet on the service side is above the height of the shower pan so there is no way to connect them. The low outlet for the shower requires a pretty flat container, like the standard RV totes or perhaps the small, 2.5 gallon, Aquatainer. Particularly if camping on a site that requires lowering the tongue for leveling.
Here's a photo of the area showing the cassette and shower drain just below the potty compartment door.