help for programing ADC12

Hello,

i'm new to using msp430fr5969 i'm trying to program the ADC12.

whenever i try to compare the internal supply of the MSP430 if it's > 2.5v the green led is turned on else the red led is turned on so i initialize the ADC12 but i

don't now what i put as internal channel.

here is my code.

		  // Configure ADC12
		  ADC12CTL0 = ADC12SHT0_2 | ADC12ON | ADC12MSC;
		  ADC12CTL1 |= ADC12SHP | ADC12CONSEQ_1;    // ADCCLK = MODOSC; sampling timer
		  ADC12CTL2 |= ADC12RES_2;                  // 12-bit conversion results
		  ADC12IER0 |= ADC12IE1;                    // Enable ADC conv complete interrupt
		  ADC12MCTL0 |= ???????
		  ADC12CTL0 |= ADC12ENC | ADC12SC;        // Start sampling/conversion
                  unsigned int result = ADC12MEM0 ;


    // Power Test
    if ( result < 3600 )
    {
    //  turn green led on
    }
    else
    {
       // turn red led on
    }