I have 2010 Alphard and I need main light bulbs, what replacement bulbs should I buy please

The bulbs are listed on top of the headlamp.

You need D4S bulbs

@Lally did this solve your question?

@Lally

On the 2010 Alphard the factory main dipped beam is typically a HID setup, and that uses D4S bulbs (as Chris said). Best way to be 100 percent sure is to look at the sticker on top of the headlamp or pull the bulb and check the marking, as some imports have had lamp units swapped over the years.

A couple of practical points before you order:
If it has HID D4S, do not fit D2S as they are not interchangeable (different ballast and no mercury in D4S). Also worth replacing in pairs because an old bulb and a new one will often look different in colour and brightness.
If yours turns out not to be HID (some conversions exist), then it will be a different bulb type altogether, so that label check matters.

If you can, post whether your lights are HID with a ballast under the lamp and whether the bulb cap says D4S, and we can confirm. Let us know if that sorts it.