ref for react-player works on codesandbox but breaks locally

I'm trying to make a player with my own controls, and as I was looking at the demo code for react-player, I saw I had to use ref to play the video from a certain place with a range input. Documentation here

In the demo app, ref is used in this way:

  ref = player => {this.player = player}

Then it's passed to the ReactPlayer component

   <ReactPlayer
       ref={this.ref}
       className='react-player'
          ...
    />

When I tried to do the same, it breaks, but as I was putting the code on CodeSandbox to submit it here as a question, I discovered it works perfectly.

Locally, I get this error: "Uncaught TypeError: Cannot set properties of undefined (setting 'player')" . What can I do to make it work locally just like it works on CodeSandbox? The code is absolutely the same, so I'm scratching my head here. Edit: Might be because it's using this in something that isn't a Class, but how do I do it in a function then? And why would it work in CodeSandbox?

Link to CodeSandbox / Link to what I have locally on Github

Follow React API and use useRef hook to handle refs.

export default function FullPlayer() {
  const playerRef = useRef();

  const handleSeekMouseUp = (e) => {
    // ...
    playerRef.current.seekTo(parseFloat(e.target.value));
  };

  return (
    <div>
      <ReactPlayer
        ref={playerRef}
        className="react__player"
        url="https://www.youtube.com/watch?v=wp43OdtAAkM"
        playing={state.isPlaying}
        loop={true}
        played={state.played}
        controls={false}
      />
      {/*...*/}
    </div>
  );
}