Does the M13A have an oil pressure sensor?

Hang on a minute. You fitted a sandwich plate without the proper tools, in order to fit an oil temperature sensor, presumably so you can obsess about looking after your engine, and in doing so nearly seized your engine? There's a lesson to be learned there.

As Fordem says, if the light didn't come on you never lost oil pressure. The test for if the oil pressure switch (it's a switch, not a sensor) is working correctly, and that the engine has oil pressure, is that the light is on with the ignition on and goes off once the engine is running. It's a foolproof system.

Also "the engine wasn't damaged since I run 5w30" doesn't make any sense.

yeah i learnt my lesson for sure, we were stupid and forgot our tools but wanted to fit the part on anyway.
i want to install the sensor because i want to know the oil temp, since i'll be modding the engine and doing a lot of stuff to it and because i like the aesthetic to it.
the thing about it not getting damaged because of the oil is that with 5w30 it resisted well to the temps and stuck to the parts even tho there was almost none in the engine. a buddy of mine ran 20w50 and his engine blew when he was in the same situation (he got tehere for different reasons tho)
also i didn't know about the whole oil pressure switch thing, i thought there would be a sensor or something of the sort, i'm still learning stuff since i do many things by myself to try and learn. obviously i watch tutorials and ask mechanics for their opinion before doing anything

If we're going to talk about oil "resisting well to temperature", the 20w50 is going to "resist better" than 5w30. Your buddy either had less oil than you did or ran his engine longer without oil than you did.

idk man, i just know the little jimny didn't die that day and i'm happy for that, i'm still ignorant about a lot of stuff and am trying to learn