title: using axios on method post requesting to server API, but on header in general it show Request Method: OPTIONS
body: <pre><code>  let email=values.email;
  let password=values.password;
  let input = {
          'email': email,
          'password': password
      };
  
      axios({        
           headers: {
              'Content-Type': 'application/json; charset=utf-8'
           } ,          
          method:'POST',
          url: "http://localhost:3001/user/login",
          data:{
              'email': email,
              'password': password
          }
      }).then(function (response){
          console.log(response);
  
      })
      .catch(function (error) {
  
      });
  </code></pre>
  
  <p>So why it show OPTIONS on request method when we use header Centent-type: application/json</p>
  
  <p><a href="https://i.stack.imgur.com/BGoaE.png" rel="nofollow noreferrer">enter image description here</a></p>