1. First you need to have installed and activated the instagram feed plugin that comes bundled with the theme: https://wordpress.org/plugins/instagram-feed/
2. Go to the instagram feed panel and click on the big blue button to connect your WordPress with instagram. Please note that you have to previously login to instagram with your browser.
3. Go to the Theme Options panel via Appearance->Theme Options and click on the Instagram Feed tab, here you must enter your Instagram ID, please be careful to enter a number for the ID and NOT your username. You can get this number from the "Instagram Feed" plugin settings (screenshot above), and in the last input field add the link to your profile on Instagram (screenshot below).
If you still struggle with the instagram ID, then please use this online tool to get your instagram ID: https://smashballoon.com/instagram-feed/find-instagram-user-id/
After you finish, simply save theme options and that's it, the instagram feed will show in the footer area.