Howdy, the angel eye/halo ring bulb is an H8 bulb, could find those at any parts store. A lot of people change these for whiter LED options but you can use whatever floats your boat.
OEM PN here, it's #5:
https://www.realoem.com/bmw/enUS/sho...diagId=63_1294
Instructions here:
https://www.newtis.info/tisv2/a/en/e...dlight/PGsxLfW
The space is a little tight due to the oil cooler lines being in the way