<p>I have a problem configuring mercure using vue and symfony. I'm using mercure hub attached in symfony cli. In the .env file I changed the url for mercure to use http as this would cause certificate errors (provided by symfony). </p> <p><strong>.env</strong></p> <pre class="brush:php;toolbar:false;">MERCURE_URL=http://localhost:8000/.well-known/mercure MERCURE_PUBLIC_URL=http://localhost:8000/.well-known/mercure MERCURE_JWT_SECRET="!ChangeMe!"</pre> <p>When I open the symfony application in the browser (e.g. http://localhost:8000) and add the following script in the console for testing: </p> <pre class="brush:php;toolbar:false;">const eventSource = new EventSource('http://localhost:8000/.well-known/mercure?topic=' encodeURIComponent('http://example .com/books/1')); eventSource.onmessage = event => { // This function will be called every time the server publishes an update console.log(JSON.parse(event.data)); }</pre> <p>It works and I can post some changes in other tabs. However, when I do the same in my vue application located at http://localhost:8080, the console shows the following error: </p> <pre class="brush:php;toolbar:false;">Access to resource at 'http://localhost:8000/.well-known/mercure?topic=http://example.com/books/1 ' from origin 'http://localhost:8080' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.</pre> <p>Also, I have two more questions:</p> <ol> <li>Why do I get a 401 error when I paste the jwt token into the env, but not when using the above jwt token? </li> <li>Why can't I use symfony serve with https? I encountered "TransportException: fopen(): Unable to locate certificate CN" error. </li> </ol></p>