vw T5 2.5 TDI - damaged oil pressure sensor, or maybe it should be?

Hello
I have been the owner of the T5 2.5 TDI 130 KM 4 Motion for two years. The car was bought from Tauron and is used recreationally as a motorhome. It was sharply tortured by the previous owners. Among other things, the oil pan is welded and this is probably not the first one - it has an unconnected oil level sensor - it looks like the oil pan has already been replaced. But the problem is different - today I noticed that the ignition oil pressure light is off (and it has been since I got the car). Ie lights up for a second after turning the key (and this confused me) but lights up with other controls - that is, such a test of clocks. Later, only the no charging indicator lights up. Question - should it shine? or is it such a smart engine that lights up the indicator when the pressure is low during operation? The computer does not show any errors. Where's the pressure sensor?
thank you in advance and best regards

I have octavie and in the manual says "The oil warning light stays on for a few seconds after switching on the ignition. If the light does not go out after starting the engine or starts flashing while driving, stop the car and turn off the engine"

Yes, it is known that after the engine starts it will go out. I do not light up at startup.
But this is how it should be - YouTube helped - there are a lot of videos from running t5 with this engine and all the same as for me e.g.
https://www.youtube.com/watch?v=prJ-5NPb8v8
The lamp goes out before starting even though the sensor definitely gives a low signal (actually no oil pressure).

There is an oil level sensor in the bowl.
The pressure sensor is as I remember well behind the air conditioning compressor.
Up to 2 thousand revolutions even as in the engine there will be no oil, the lamp will not come on. This is the car.

Well, it's a car that if you save fuel, you can blur the engine like an oil pump will fall and the indicator light will not come on. Most VW have it, probably also some merce state that lubrication is based on a decrease in the oil level in the engine after starting and some French respond to the signal from the pressure sensor after 30km (someone on the forum wrote how to simulate such a failure). Generally, there is nothing to worry about, because lubrication failures are very rare.

Ok sensor case seems to be taken care of. I have one more question - is it possible for the factory to give an oil pan with a level sensor, oil without connecting it to anything (there is no beam)? This is a simple 130KM version with clocks without a display.

This is not possible, certainly it is more possible that the Tauronists broke many bowls and put on anything, but the presence of a sensor that is not connected, does not bother.