I don't have the same make or model as yours, but we are in the process of having a washer and dryer installed in ours. The washer and dryer location is along the outer wall, and we are going with a vented dryer. That means a hole will have to be cut in the side of the trailer to accommodate the dryer vent.
Looking at the floor plan of your model:
click here, it looks like you'll need to run a duct from the middle to an outer wall, most likely, through that cabinet, or under it, if there is no provision to take the ductwork straight down through the floor.
Go to 4:45 (4 minutes, 45 seconds in the video). Not much info, but shows a good shot of the washer/dryer area. This is a 2017 model video, but looks like not much has changed since then. It's still the same floor plan. More current videos did not show the washer/dryer prep area as well.
A couple things you may want to pre-prep before installing; lay a sheet of plywood under the washer on the floor so the feet of the washer won't rub holes in the floor, either with use, or when traveling.
Second, that area is going to get it's share of "bounce" when traveling. Find a way to secure the washer and dryer so they won't bounce around and slide away from the wall.
Good luck.