My question involves a child custody case from the State of: Oklahoma

I completed a modification to my child support in October and have been paying the new amount with no problems until today. I received a letter from my job that told me they had received a National Medical Support Notice and will be adding my children to my medical coverage. During my modification hearing I was advised by the child support worker to go with the cash medical option as opposed to carrying them on my medical insurance so I agreed and have been paying a set amount along with my normal child support. I have my modification paperwork, and it shows the cash medical. So I am a bit unsure of how to proceed at this point. Does the cash medical override the need to carry insurance as I was told? If I am being made to carry insurance, will that cancel out my cash medical? A bit confused on all of this. Just when I thought I had the modification out of the way it seems to change up on me. Thank you for any info you guys can provide, and also I will be calling child support in the morning to get more information but I wanted to see if I could get any info beforehand.