Hi Lena, If a petition for dissolution has been filed, either by you or your husband, you can file what's called a Motion for Temporary Relief to request child support while the divorce is pending. Look for FORM 12.947(a), on the Florida Supreme Court's site - www.flcourts.org .
If neither of you has filed a petition for dissolution of marriage, and you are not contemplating divorce, you can file a Petition for Support Unconnected with Dissolution. If that is your situation, Look for FORM 12.904(b), also on the Florida Supreme Court's site - www.flcourts.org .
Instructions for both forms are on the Supreme Court's site. This is not meant to be legal advice. and is what should be common knowledge.