Have any of you mommas gone through a child support review through the courts? If so... what happens if you don’t show up?

The reason why I don’t want to show up is cause I just feel as if I’m such a pushover, he wants to make an agreement like we did 3 years ago and he never complied with it.. so I’m not trying to make any type of agreement.. and I know it is definitely going to increase cause he got a higher position.... so I’m just looking for some advice .