Customizer Not Working

Hi
I clicked the “Customize” button on the admin toolbar but I got this error:

There has been a critical error on your website please check your site admin email inbox for instructions

The error log I get in the email:

The E_ERROR error is caused by the code on line 302 of the file /storage/ssd1/001/17050***/public_html/wp-content/themes/blocksy/inc/customizer/init.php. Error message: Uncaught Error: Call to undefined function wp_use_widgets_block_editor() in /storage/ssd1/001/17050***/public_html/wp-content/themes/blocksy/inc/customizer/init.php:302
Stack traces:
#0 /storage/ssd1/001/17050***/public_html/wp-includes/class-wp-hook.php(292): {closure}()
#1 /storage/ssd1/001/17050***/public_html/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()
#2 /storage/ssd1/001/17050***/public_html/wp-includes/plugin.php(484): WP_Hook->do_action()
#3 /storage/ssd1/001/17050***/public_html/wp-admin/customize.php(123): do_action()
#4 {play}
   thrown

Last change:
– Change domain
– Update WordPress but failed

I tried it with another theme and there is no error, the error only appears on your theme

The page I need help with: [log in to see the link]