We do not know if the LED already has current limiting. It might have two 3V chips in series and a current limiting resistor with 3V across it.
Or it might have three 3V chips in series with nothing to limit the current.
Who knows? The datasheet of the COB LED will show all the details that are missing in this thread.
Jamshi, please post the datasheet.
AliExpress has a Cob LED for illegally modifying the lighting on a car. It shows two parallel strips of 3 LEDs in series. They say, "Use voltage of 9V - 12V" and say, "use current of 1000mA to 1500mA". It is rated at 15W to 18W.
They say, "Cooling temperature is not more than sixty degrees." They also say, "They may burn out if they receive enough power with no cooling , And if you use it for a long time, please give them colling!!!" That is their Chinlglish with no details.