From the attached, this looks like the same fitting that the long oil filter bowl bolt threads into. If so, it has no seal ring. In fact according to the BBB, you are not supposed to take it off. It is factory "glued" in with possibly an epoxy. The reason being is that it cannot ever turn, otherwise you cannot remove the bowl bolt from below. So they glued it in permanently.
I have thrown caution into the wind and have removed these and I use a epoxy putty to reseal. I take a small amount of putty and roll it into an "earthworm" shape, and then finally into a doughnut. This goes on the bolt under the head. Then torque it like you would any other fitting quickly before the epoxy hardens. No leaks.