Ok, that is easy to do. You just need to locate a convenient place on the engine, then drill and tap a hole for a pressure fitting.
Granted in some cases it may not be as easy as removing a backplate to drill and tap a hole in it. But as long as the hole leads to the crankcase bottom inside, then you are in business. Your engine likely has the heat isolation block on it and that block should have a hole in the crankcase matching it. You can drill a small hole to meet up with the hole in the block and then drill and tap that smaller hole for a fitting. You could likely do a light press fit of a length of brass tubing into the hole and use it for a fitting too.