PHP 8 compatibility issue

When we try to switch to PHP 8, we’re getting this error:

Fatal error
: Uncaught TypeError: Cannot access offset of type string on string in /home/example/domains/example.com/public_html/wp-content/plugins/ultimate-social-media-icons/libs/sfsi_widget.php:235 Stack trace: #0 /home/example/domains/example.com/public_html/wp-content/plugins/ultimate-social-media-icons/libs/sfsi_widget.php(51): sfsi_check_visiblity() #1 /home/example/domains/example.com/public_html/wp-includes/class-wp-widget.php(394): Sfsi_Widget->widget() #2 /home/example/domains/example.com/public_html/wp-includes/widgets.php(835): WP_Widget->display_callback() #3 /home/example/domains/example.com/public_html/wp-content/themes/genesis/lib/structure/sidebar.php(24): dynamic_sidebar() #4 /home/example/domains/example.com/public_html/wp-includes/class-wp-hook.php(308): genesis_do_sidebar() #5 /home/example/domains/example.com/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters() #6 /home/example/domains/example.com/public_html/wp-includes/plugin.php(517): WP_Hook->do_action() #7 /home/example/domains/example.com/public_html/wp-content/themes/genesis/sidebar.php(34): do_action() #8 /home/example/domains/example.com/public_html/wp-includes/template.php(783): require_once(‘/home/example/…’) #9 /home/example/domains/example.com/public_html/wp-includes/template.php(718): load_template() #10 /home/example/domains/example.com/public_html/wp-includes/general-template.php(136): locate_template() #11 /home/example/domains/example.com/public_html/wp-content/themes/genesis/lib/structure/layout.php(333): get_sidebar() #12 /home/example/domains/example.com/public_html/wp-includes/class-wp-hook.php(308): genesis_get_sidebar() #13 /home/example/domains/example.com/public_html/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters() #14 /home/example/domains/example.com/public_html/wp-includes/plugin.php(517): WP_Hook->do_action() #15 /home/example/domains/example.com/public_html/wp-content/themes/genesis/lib/framework.php(87): do_action() #16 /home/example/domains/example.com/public_html/wp-content/themes/metro-pro/front-page.php(70): genesis() #17 /home/example/domains/example.com/public_html/wp-includes/template-loader.php(106): include(‘/home/example/…’) #18 /home/example/domains/example.com/public_html/wp-blog-header.php(19): require_once(‘/home/example/…’) #19 /home/example/domains/example.com/public_html/index.php(17): require(‘/home/example/…’) #20 {main} thrown in
/home/example/domains/example.com/public_html/wp-content/plugins/ultimate-social-media-icons/libs/sfsi_widget.php
on line
235