AD7177-2 REF(-) usage

Hi

I understand VREF=REF(+)-REF(-)

But, I'm NOT sure how REF(-) is used.

So, would you teach if my setting works correctly for AD7177-2 below.

ADD1=AVDD2=IOVDD=REF(+)=2.5V, AVSS=REF(-)=-2.5V and analog input range: ±2.5V/gain