Hello

As a rule, replacement lamps for ovens are always of the same type. Since you want to change the bulb yourself, you can remove the old or defective lamp in the oven.

Then you can directly compare the size (length, width, diameter, etc.), power (W) and the base (E14)...

I am not aware of any replacement lamps in the form of LEDs or other energy-saving technology for use in ovens. Presumably the temperature (LED has electronics and plastic plastics) is too high for their use.

For example, there are LED products for the refrigerator or other appliances with these specially small light sources.

I don't think the greatest amount of energy will be lost in the oven, there are certainly other places in the house or flat where you can save energy and money.

Greetings
Electrician