How to add social media link to html?

How to add social media links to HTML?

Social Media

        <a href="https://www.facebook.com/user" target='blank'>

        <a href="https://www.instagram.com/user" target='blank'>

        <a href="mailto:user@gmail.com?subject=Message from website" target='blank'>

            <img src="/images/social-media-icons/mail.png" alt="Mail" />

<a href=mailto:xxx@gmail.com?subject="HTML link">Click here to send us an email!!!</a>