What is the iupac name of CH3CH(CH3)COCONHBr?

CBSE Class 11
1

What is the iupac name of CH3CH(CH3)COCONHBr? Why can we not use oxo instead of keto as prefix?

2

The IUPAC name of CH3CH(CH3)COCONHBr:
image
When (C=O) group is adjacent to the functional group then we oxo as a prefix.