trying to get my daughter dad on child support

I’m trying to get my daughter dad on child support he’s an absolute awful dad I’ve raised our daughter 3 years 5 months into my pregnancy and said he didn’t want nothing to do with her he’s always coming and going and isn’t mature enough to act like a dad he’s parents are telling me to get child support and idk what I am doing will someone plz explain how I do things or go about it bc quite frankly he doesn’t need to be in her life I have several people who can back up what kinda person he is and how they don’t like him