How to know which “TEMP_SENSOR_0” value for pre-built custom printer

I got a prebuilt custom printer which I am trying to get working. I am currently trying to configure Marlin for it and I am kind of stuck on the TEMP_SENSOR_0 constant since I don't know that thermistor I have.

I tried to ask the person who gave me the printer, but he doesn't know. How can I tell?

Can I try to pull it from the current configurations somehow using Pronterface?

I tested with values 1 and 5 and I am getting a Error:Heating failed, system stopped! Heater_ID: 0 error whenever I reach ~150 °C; I don't know if this info helps.