useImperativeHandle-usage.tsx

import MyInput, { MyInputHandles } from './MyInput';

const Autofocus = () => {
  const myInputRef = useRef<MyInputHandles>(null);

  useEffect(() => {
    if (myInputRef.current) {
      myInputRef.current.focus();
    }
  });

  return <MyInput ref={myInputRef} />
}

it looks like your code is in error. otherwise the typescript would not show an error
https://tinyurl.com/46w49fsj