Here's the return to tank via a short piece of hose
the 4 bolts that you can see on the side of the heater is where my pump is fitted.
Looking good Ime sure you will be very happy with it 😂😂😂😂 if I dont connect my return to tank within a couple of muinets maximum mine will shut down , yours looks a bit different to mine I expect yours is a newer model quality kit enjoy