Canning with candles I am not sure about the right terminology as I am not a native speaker, but is it possible to conserve solid food in a jar with a candle?

Boiling is used to decrease air and for the food to be well conserved it must not have much oxygen. The food is suffocating. A tea candle placed inside will suck the air too and will extinguish when there is no sufficient air inside.
The short answer is: No.

The more elaborate answer is that certain bacteria are anaerobic and food needs to be heat treated to ensure it can be safely stored. Especial mention: Clostridium botulinum which leaves deadly toxins.

The tealight inside the jar will not produce the heat needed for pasteurization.