Mercure and vue subscribing

im having some difficulties with mercure and Vue. I want to subscribe from vue to my mercure topic but im still getting 401 errors

Im running my mercure as docker image:

sudo docker run \
                     -e MERCURE_PUBLISHER_JWT_KEY='!ChangeMe!' \
                     -e MERCURE_SUBSCRIBER_JWT_KEY='!ChangeMe!' \
                     -e ALLOW_ANONYMOUS=1 \
                     -p 1337:80 \
                     -p 1338:443 \
                     dunglas/mercure

Also my symfony publisher:

class PublishController extends AbstractController
{
    /**
     * @param HubInterface $hub
     * @return Response
     * @Route("/push",name="/push")
     */
    public function publish(HubInterface $hub): Response
    {
        $update = new Update(
            '/chat',
            json_encode(['message' => "mercure push"]),
        );
        $hub->publish($update);
        return new Response('published!');
    }
}

And there's my part of Vue where i try to subscribe:

    document.addEventListener('DOMContentLoaded',function(){
      let url =new URL(https://localhost:1338/.well-known/mercure)
      url.searchParams.append('topic','/chat');
      const eventSource = new EventSource(url);
  
    eventSource.onmessage = (event) =>{
      console.log(event)
    }
    })

error code:

But when i will enter via link and later on /push endpoint from my backend im getting some data My guess is that i have something wrong with auth but to be honest im lost, i dont know where should i look for clues Thanks for any help!

Well I solved problem. There were two reasons for why it wasn't working:

1. I added polyfill to my EventSource in Vue, and added authorization jwt key: https://www.npmjs.com/package/event-source-polyfill
2. I've created reverse proxy with nginx to resolve cors errors

And these two things solved my problem, still thanks @Francisco for your answer