There are usually
two low point drains, one red for hot and one blue for cold. They can either have caps on the ends or some have a valve on the end. SOME
have the valve inside the trailer and just a hose hanging out underneath. For an Apex Nano, I'd bet on just plugs. You can see my plugs in this pic (not very well, though):
In addition there should be a FW tank overflow, it could be any color, but is usually white.
Then you may or may not have a FW drain hose. Most FW drains are either just a plug or have a valve installed similar to this one, although there are some other styles:
My FW tank had the plug, located right between the axles. I installed an elbow and some PEX and brought it out to a valve like above. You can see it in the first pic; I painted it black and it pretty much disappears into the rest of the plumbing underneath.