Location: Sarnialabad, Peoples Republik of Canuckistan
Posts: 1,251
Black removable panel under dash adjacent driver's side cockpit wall. OBD II port is inside. That's where it is on my later model. Right near the hood release lever.
As Winterbagoal noted and assuming it's similar to our 2016 Era, it's next to the hood release and fuse panel by the driver's left leg. Attaching a shot of ours - the preview shows the photo in the wrong orientation, you may need to rotate it to make sense of it.
If you are asking where the OBD port is, you are probably thinking about an OBD reader. I bought an iCarsoft MBII scanner and it has come in handy when the dreaded engine light comes on. The automatic regeneration of the DPF is suspended anytime the check engine light is on. The scanner can be used to manually regenerate the DPF when the engine component fault is not otherwise fatal. This is critical when you are more than 250 miles from a MB dealer who can (has time to) fix the non-fatal component. I thought my days of roadside vehicle repair were far behind me until I bought the Sprinter. Now I bring the scanner and tools just in case. At least my wife is impressed...