Lab power supplies or cheap, tiny voltage boosters with usually a one ohm, one watt resistor in series. The boosters are ran off 12 volt supplies and gets me to the 24 volts or so that I need to run the Vero 10's. Boosters:

https://www.amazon.com/dp/B099DK5R9C?psc=1&ref=ppx_yo2ov_dt_b_product_details

I run them mainly constant voltage with a resistor and not constant current like how most COBs are ran. I'm running them at 200 mA at most like this.

Using more than one ohm of resistance in series with the Vero 10 makes the circuit more temperature stable but less efficient.