title: has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource express react client
body: <p>Tryed a couple links here, some tutorials and documentations and running after my tail because i'm not getting anywhere.</p>
  <p>Service code:</p>
  <pre><code>
  const express = require('express')
  const cors = require('cors');
  
  const app = express();
  const router = express.Router()
  
  app.use(json());
  app.use(router);
  const PORT = process.env.PORT || 5000
  var server_host = process.env.YOUR_HOST || '0.0.0.0';
  
  const corsOptions = {
      origin: ['http://localhost:3000', 'https://swapee-interface.vercel.app/', 'https://app.swapee.io'] 
  }
  
  app.listen(PORT, server_host, () =&gt; {
      console.log(`server is listening on port: ${PORT}`)
  })
  
  router.get('/:chain/:dex/:token', cors(corsOptions), async(req, res) =&gt;{
   //some logic
  })
  </code></pre>
  <p>Client code:</p>
  <pre><code>    useEffect(() =&gt; {
          axios({
              url: `https://swapee-api.herokuapp.com/${items.chain}/${items.dex}/${items.address}`,
              method: 'get',
          })
          .then((res) =&gt; { 
              console.log(res)
              setTokenPrice(res.data) })
      }, [])
  
      useEffect(() =&gt; {
          axios({
              url: `https://swapee-api.herokuapp.com/${items.chain}/${items.dex}/${address}`,
              method: 'get',
          })
              .then((response) =&gt; {
                  console.log(response)
                  setCoinPrice(response.data)})
        // empty dependency array means this effect will only run once (like componentDidMount in classes)
        }, []);
  </code></pre>
  <p>Error:</p>
  <pre><code>Access to XMLHttpRequest at 'https://swapee-api.herokuapp.com/137/Quickswap/0xe9e7cea3dedca5984780bafc599bd69add087d56' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
  </code></pre>
  <p>Maybe i need to be specific about the methods that i'm allowing but i think that i already tryed.</p>