@Christine, first off theme does not support the footer widgets. In order to enhance your theme with this feature, you would need to add some custom codes to register new sidebar in footer and thus make compatible to add widgets into it.

Hints: register new sidebar, add sidebar / widget code in (inc/hooks/footer.php) . Needs design workarounds on widget elements needed. Consider making a Child Theme as a safe approach to edit the code.

If you won’t feel comfortable playing with codes, consider Hiring a Customizer to enhance your theme with needed feature in a safe approach.

Thank you