Enfold Child Version 1

I had problems with my website. The code, sent through wordpress is the following:

Wenn du Hilfe bei diesem Problem suchst, wirst du möglicherweise nach einigen der folgenden Informationen gefragt:
WordPress-Version 6.1.1
Aktives Theme: Enfold Child (Version 1.0)
Aktuelles Plugin: (Version )
PHP-Version 8.1.13

Fehler-Details
==============
Ein Fehler vom Typ E_ERROR wurde in der Zeile 4 der Datei /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-content/themes/enfold/config-layerslider/LayerSlider/wp/widgets.php verursacht. Fehlermeldung: Uncaught Error: Call to undefined function create_function() in /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-content/themes/enfold/config-layerslider/LayerSlider/wp/widgets.php:4
Stack trace:
#0 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-content/themes/enfold/config-layerslider/LayerSlider/layerslider.php(53): include()
#1 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-content/themes/enfold/config-layerslider/config.php(87): include(‘/home/webpages/…’)
#2 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-includes/class-wp-hook.php(308): avia_include_layerslider(”)
#3 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array)
#4 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#5 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-settings.php(617): do_action(‘init’)
#6 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-config.php(116): require_once(‘/home/webpages/…’)
#7 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-load.php(50): require_once(‘/home/webpages/…’)
#8 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-admin/admin.php(34): require_once(‘/home/webpages/…’)
#9 /home/webpages/lima-city/contactimpro/wordpress_de-2017-03-10-47a8a2/wp-admin/index.php(10): require_once(‘/home/webpages/…’)
#10 {main}
thrown

It seems, that the Enfold Child Theme, Version 1 is not compatible to the WP-Upadate and PHP 8. Is it necessary to update it? And how can I do that? And does this update change my original design, which worked for years (for I’m no webdesign specialist)?