title: Email OTP verification
body: <p>I am new to react js and firebase so I don't know how to get OTP through email. This code is only  sending verification link to email but I want OTP in email.What changes I have to make in this code for getting OTP.
  Here is the Code-</p>
  <pre><code>const signup = () =&gt; {
    auth.createUserWithEmailAndPassword(user.email, user.password)
      .then((userCredential) =&gt; {
        // send verification mail.
        userCredential.user.sendEmailVerification();
        //auth.signOut();
        alert(&quot;Email sent&quot;);
      })
      .catch(alert);
  }
  </code></pre>