Here it is sorry..
But I thought Voltage needs to be limited too as it can bea above14v and i planned to use the LED at 13V / 3,5 A. But as i said the voltage of the panel can get as low as 12 V for the worst Case with 400 w/m2 irridiance and 75 Celsius Panel temp and in this Case i need to Booster the voltage a Bit altough it needs to lowered the Rest of the time.
Assuming these are actual LEDs: The forward voltage is 12V. Meaning your supply needs to be something above that. The current is 3750 ma. You woul need to limit the surrent to that. The simplest way to do that is using a resistor but with a 21 panel you would need a 2.4Ohn resistor @ 33W. That is impractical.
They make LED drivers for such a purpose that is a switched mode supply. Far more efficient than a resistor.
But you panel is only 21volts @150W. That means , under ideal conditions, the panel is only going to be able to supply 7 amps. You will likely only be able to light one of those LEDs in real life conditions and will probably not be for more than a few hours a day..