Error while adding custom snippet

Hi,

I added this code in code snippet next moment it started showing this
”
Fatal error: Uncaught Error: Class ‘SI_Invoice’ not found in /home/h7cc1beh25ov/public_html/wp-content/plugins/code-snippets/php/snippet-ops.php(361) : eval()’d code:5 Stack trace: #0 /home/h7cc1beh25ov/public_html/wp-content/plugins/code-snippets/php/snippet-ops.php(361): eval() #1 /home/h7cc1beh25ov/public_html/wp-content/plugins/code-snippets/php/snippet-ops.php(450): execute_snippet(‘// create the p…’, 13) #2 /home/h7cc1beh25ov/public_html/wp-includes/class-wp-hook.php(286): execute_active_snippets(”) #3 /home/h7cc1beh25ov/public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #4 /home/h7cc1beh25ov/public_html/wp-includes/plugin.php(465): WP_Hook->do_action(Array) #5 /home/h7cc1beh25ov/public_html/wp-settings.php(394): do_action(‘plugins_loaded’) #6 /home/h7cc1beh25ov/public_html/wp-config.php(104): require_once(‘/home/h7cc1beh2…’) #7 /home/h7cc1beh25ov/public_html/wp-load.php(37): require_once(‘/home/h7cc1beh2…’) #8 /home/h7cc1beh25ov/public_html/wp-admin/admin.php(34): require_onc in /home/h7cc1beh25ov/public_html/wp-content/plugins/code-snippets/php/snippet-ops.php(361) : eval()’d code on line 5
The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.”

How to solve this?

Regards

Prashant…