S124 ADC Vref

Good Day

I am trying to use the ADC with external Vref on the S124 (R7FS124773A01CFL).

When selecting P011 and P010 as the VREFL0 and VREFH0 in the ADC module there is red blocks next to P011 and P010 under the pins section.

What am I doing wrong in setting up the VREFL0 and VREFH0 pins.

Any advice will be greatly appreciated.

Regards

Brian