title: SendGrid : How to set dynamic link value of a button
body: <p>I am using sendGrid to send an email verification mail to a user, when user click on a "Verify" button it will be redirected to another link, I have successfully sent an email but I can't figure out how can I make button dynamic?</p>
  
  <p>I read about <code>substitution</code> and don't know how to use this with button 
  I have added following line to my code </p>
  
  <pre><code> email.addSubstitution(VERIFY_TOKEN_KEY, new String[] { token.getToken() });
  </code></pre>
  
  <p>And this is my Button code on SendGrid </p>
  
  <pre><code>&lt;a style="background-color:#51a9a4;border:1px solid #333333;border-color:#333333;border-radius:6px;border-width:1px;color:#ffffff;display:inline-block;font-family:arial,helvetica,sans-serif;font-size:16px;font-weight:normal;letter-spacing:0px;line-height:16px;padding:12px 18px 12px 18px;text-align:center;text-decoration:none;"
    href="-verifyLink-" target="_blank"&gt;Verify&lt;/a&gt;
  </code></pre>
  
  <p>What should I write in href?</p>