title: How to access Firebase from http://localhost:3000
body: <p>I'm developing a React app, and I get this error when trying to sign in to Firebase using their email auth provider.</p>
  
  <pre><code>Failed to load https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyPassword?key=.....: 
  Response to preflight request doesn't pass access control check: The
  'Access-Control-Allow-Origin' header has a value 'https://localhost:3000' 
  that is not equal to the supplied origin. Origin 'http://localhost:3000'
  is therefore not allowed access.
  </code></pre>
  
  <p>(Notice the <code>https</code> on line 3 versus <code>http</code> on line 4)</p>
  
  <p>It looks like they changed <code>Access-Control-Allow-Origin</code> from <code>*</code>, to the <code>https</code> version of whatever domain you're calling from?</p>
  
  <p>Does this mean I now need to configure my React app to run as <strong>https</strong>://localhost:3000?</p>