Anyone work with LED lights

The basics of LEDs

An LED is exactly what the name "says" .........."Light Emitting DIODE"

It's a diode.

When you hook a diode to DC voltage, one direction it does not conduct current.

When you hook the diode up in the opposite direction, it becomes a "dead short" in basic terms. To prevent this "dead short," LEDS must have a current limiting resistor.

"12 volt" LEDs are in reality an LED with a limiting resistor "inside" to limit current.

You can buy LEDS "bare" that is with no limiting resistor, or with resistors configured for different voltages, in your case 12V

So the answer is, if you were to buy diodes WITHOUT resistors, you could wire them in series. You would then have to provide a resistor to handle the current and to limit the current properly