Multi-step wizard with form children, how to wait for child submit to complete?

[nfiacco]

I'm building a reusable multi-step wizard component, which provides a standard footer with navigation. It looks something like this:

export const MultiStep: React.FC<MultiStepProps> = ({ steps }) => {
  const stepSubmitRef = useRef<HTMLFormElement>(null);
  const [stepIdx, setStepIdx] = useState<number>(0);
  const nextStep = () => {
    stepSubmitRef.current?.submit(); // How do I wait for this submit to complete?
    setStepIdx(stepIdx => stepIdx++);
  }

  return (
    <div>
        {currentStepFn(stepSubmitRef)}
      <div>
        <button id="back"/>
        <button id="forward" onClick={nextStep}/>
      <div>
    </div>
}

I'm not sure if there's a good way to wait for the submit of the child step to complete before navigating to the next step. Any ideas?