Raspberry Pi 4B giving 0.3V output when GPIO is set to True or High

I have a Raspberry Pi 4B, 4GB version. When I try to run the following code it gives 0.3V output. I mean it works, on-0.3V, off-0V. But I need 3.3V output. I measured it with a voltmeter, as the interested device was not working getting only 0.3V from Pi.

import timeGPIO.setmode(GPIO.BCM)GPIO.setwarnings(False)GPIO.setup(21,GPIO.OUT)print ("LED on")GPIO.output(21,True)time.sleep(10)print ("LED off")GPIO.output(21,False)