How can implement SMTP with postmarkapp ?

Searched lot on internet but didn't get any sample code

<script src="https://smtpjs.com/v3/smtp.js"></script>
Email.send({
                    Host: "smtp-broadcasts.postmarkapp.com",
                    Port: "587",
                    Authentication: "Plain text",
                    Username: "PM-B-xxx-xxxx",
                    Password: "z6pB-xxx",
                    Header: "X-PM-Message-Stream: xxx",
                    //SecureToken: "xxx",
                    To: "mytest@gmail.com",
                    //From: 'mytest@gmail.com',
                    Subject: "Email",
                    Body: email
                })

Please help