How I can get the high time and low time in the the ATMega328P Timer2

Hello everybody,
I am trying to learn how I program in the Arduino, I'm new in this field.
So I have this code

#include <avr/io.h>
#include <avr/interrupt.h>

int main(void)
{
	/* Set PortD bit 3 to be an output because this is the OC2B output  */
	
	DDRD = (1 << DDD3);

	TCCR2A = (1 << COM2B0); 	/* Non-PWM Mode, toggle OC2B on compare match */
	TCCR2B = (2<<CS20);		/* Timer2 Source = (16MHz)/2, period = 0.5us */
	TIMSK2 = (1 << OCIE2B);	/* Enable Timer 2 Output Compare 2B interrupt */
	
	sei();				/* Global interrupt enable */
		
    while(1)
	;
			/* Do nothing loop  */
    return 1;
}

ISR(TIMER2_COMPB_vect)
{
	OCR2B = OCR2B + 100;  /* Next toggle and interrupt in 50us */				  
}

I need to modify the program so that a 10kHz signal is produced on OC2B, but with a high time of 70uchange s and a low time of 30us.

Please can anyone help on that? And trying to explain it.
Thanks.

See: https://www.gammon.com.au/timers

look for Reply #8 ( https://www.gammon.com.au/forum/?id=11504&reply=8#reply8 )

There, following the table, you'll see an example code for setting the frequency and duty cycle of the signal appearing on OC2B.

In your case, the duty cycle appears to be 25%. Alter OCR2A, OCR2B and the pre-scaler to suit.

You should download the ATmega328p datasheet and study the parts about the Timer/Counter Control Registers you are using: TCCR2A and TCCR2B. The bits you set are to control the "Compare Output Mode" (COM) for OC2B and the "Clock Select" (CS) for Timer2. You don't set any Waveform Generation Mode (WGM) bits so the chosen mode is 0: "Normal". In that mode, the timer counts from 0 to 255 and repeats. Setting COM2B0 causes the OC2B pin to toggle each time the count passes the value in OCR2B. The ISR moves the value forward by 100 each time the compare match causes an interrupt so the effect is a square wave that toggles every 50 microseconds (100 microsecond period = 10 kHz frequency).

For 70 microseconds ON and 30 Microseconds OFF I would use a Fast PWM mode with TOP set to 199 and OCR2B set to 139. Then there is no need for an ISR.