I need help regarding Typescript to JS conversion

I am new to typescript and only have been working with react js files. Now i need to change some typescript files to js files.

Can someone explain or help me out with one of them so i can better understand how this can be achieved.

So this is a pretty simple one i think for example, what do i need to change in order to make it useable with an .js extension

The only thing marked as an error is: "as const" in the return function. But i dont know how to write this in plain js since i am also kinda new to javascript..

function usePip(ref: RefObject<HTMLElement>) {
 
  const [styles, set] = useSpring(() => ({
    x: 10,
    y: 10
  }));
  const bind = useDrag(
    ({ down, last, movement: [x, y], metaKey, ...rest }) => {
      let defaultX = 10;
      let defaultY = 10;
      if (last && ref.current) {
        const rect = ref.current.getBoundingClientRect();
        if (rect.x + rect.width / 2 > window.innerWidth / 4) {
          defaultX = window.innerWidth / 2 - rect.width / 2 ;
        }
        if (rect.x + rect.width / 2 > window.innerWidth / 1.5) {
          defaultX = window.innerWidth - 10 - rect.width;
        }
        if (rect.y + rect.height / 2 > window.innerHeight / 4) {
          defaultY = window.innerHeight / 2 - rect.height / 2;
        }
        if (rect.y + rect.height / 2 > window.innerHeight / 1.5) {
          defaultY = window.innerHeight - 10 - rect.height;
        }
        
      }
      set({
        x: down || metaKey ? x : defaultX,
        y: down || metaKey ? y : defaultY,
        immediate: down
      });
    },
    { initial: () => [styles.x.get(), styles.y.get()] }

  );
  return [bind, { ...styles, position: "fixed", left: 0, top: 0, zIndex: 99999 }] as const;
}