E_ERROR en la línea 210 del archivo

Hello, my name is Angelica and I have an Error for a really long time on my WordPress page.
I thought it was because I hadn´t updated the theme but now I purchased the last Version 5.2.1 and I have the same error.
I don´t know how to fix it, so if you could help me, please.

I would wait for your answer,

Thank you.

This is the error:

Detalles del error
==================
Se ha producido un error del tipo E_ERROR en la línea 210 del archivo /home/anyospar/public_html/wp-content/themes/enfold/includes/helper-social-media.php. Mensaje de error: Uncaught Error: Call to undefined function av_icon_string() in /home/anyospar/public_html/wp-content/themes/enfold/includes/helper-social-media.php:210
Stack trace:
#0 /home/anyospar/public_html/wp-content/themes/enfold/includes/helper-social-media.php(238): avia_social_media_icons->build_icon(Array)
#1 /home/anyospar/public_html/wp-content/themes/enfold/includes/helper-social-media.php(267): avia_social_media_icons->html()
#2 /home/anyospar/public_html/wp-content/themes/enfold/includes/helper-main-menu.php(15): avia_social_media_icons(Array, false)
#3 /home/anyospar/public_html/wp-includes/template.php(772): require(‘/home/anyospar/…’)
#4 /home/anyospar/public_html/wp-includes/template.php(716): load_template(‘/home/anyospar/…’, false, Array)
#5 /home/anyospar/public_html/wp-includes/general-template.php(204): locate_template(Array, true, false, Array)
#6 /home/anyospar/public_html/wp-content/themes/enfold/header.php(268): get_template_part(‘includes/helper’, ‘main-menu’)
#7 /home/anyospar/public_html/wp