DRL problem stabilizer is KO

[vrestihnat]

Hello, please does anyone know what the black box behind the lamp contains, see the link to the shop:
https://www.ebay.it/itm/256389020553
I assume stabilizer/regulator. Can someone share the wiring diagram for me?
Could this work?:
https://www.ti.com/product/LM2940C
Thanks for the responses, Jan