Light on amazon They don't sell one without a switch. Check the Streamlight website here to confirm.
When you look at an item, under the item's name it should say something like "Visit the [Manufacturer] Store" like here it says "Visit the Streamlight Store" and then you can click the link which will take you to an actual professional looking page like this vs some random seller with a basic storefront and selling a bunch of random crap. I guess, technically, it could be faked, but isn't very likely that they would check all the boxes.
Streamlight 88066 ProTac Rail Mount HL-X Fixed Mount Ten Tap, 1,000 Lumens, Black https://www.amazon.com/dp/B06VTLLDH4/ref=cm_sw_r_cp_api_glt_fabc_KTAQ1J1C48MHYKHZ1WN9
If you want shop around a bit, might find it cheaper.