Error: Call to undefined function get_current_screen() with Dokan

I get the following error message, after i created an vendor account
https://staging16.evooming.de/?page=dokan-seller-setup (Does not work in this way, you have to pay first 😉 )

Fatal error: Uncaught Error: Call to undefined function get_current_screen() in /home/customer/www/staging16.evooming.de/public_html/wp-content/plugins/sg-cachepress/core/Admin/Admin.php:383 Stack trace: #0 /home/customer/www/staging16.evooming.de/public_html/wp-content/plugins/sg-cachepress/core/Admin/Admin.php(284): SiteGround_Optimizer\Admin\Admin->is_plugin_page() #1 /home/customer/www/staging16.evooming.de/public_html/wp-includes/class-wp-hook.php(303): SiteGround_Optimizer\Admin\Admin->admin_print_styles('') #2 /home/customer/www/staging16.evooming.de/public_html/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #3 /home/customer/www/staging16.evooming.de/public_html/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #4 /home/customer/www/staging16.evooming.de/public_html/wp-content/plugins/dokan-lite/includes/Vendor/SetupWizard.php(121): do_action('admin_print_sty...') #5 /home/customer/www/staging16.evooming.de/public_html/wp-content/plugins/dokan-lite/includes/Vendor/SetupWizard.php(102) in /home/customer/www/staging16.evooming.de/public_html/wp-content/plugins/sg-cachepress/core/Admin/Admin.php on line 383

Can check, if there is this function, before you use it?
Something like:

/**
	 * Check if this is the SG Cachepress page.
	 *
	 * @since  @version
	 *
	 * @return bool True/False
	 */
	public function is_plugin_page() {
	
		if( !function_exists('get_current_screen') ) {
			return false;
		}
	
		$current_screen = \get_current_screen();

		if ( in_array( $current_screen->id, $this->get_plugin_page_ids() ) ) {
			return true;
		}

		return false;
	}

Thank you very much

Best Regards,
Klaus