Gutenberg for WooCommece Product Page in WordPress 6.0+

I wanted to enable Gutenberg for My Single Product Description so I followed this guide https://dev.to/kalimahapps/enable-gutenberg-edit

function activate_gutenberg_product( $can_edit, $post_type ) {

    if ( $post_type == 'product' ) {
        $can_edit = true;
    }
    return $can_edit;
}
add_filter( 'use_block_editor_for_post_type', 'activate_gutenberg_product', 10, 2 );

function enable_taxonomy_rest( $args ) {
    $args['show_in_rest'] = true;
    return $args;
}
add_filter( 'woocommerce_taxonomy_args_product_cat', 'enable_taxonomy_rest' );
add_filter( 'woocommerce_taxonomy_args_product_tag', 'enable_taxonomy_rest' );


function register_catalog_meta_boxes() {
    global $current_screen;
    // Make sure gutenberg is loaded before adding the metabox
    if ( method_exists( $current_screen, 'is_block_editor' )  $current_screen-is_block_editor() ) {
        add_meta_box( 'catalog-visibility', __( 'Catalog visibility', 'textdomain' ), 'product_data_visibility', 'product', 'side' );
    }
}
add_action( 'add_meta_boxes', 'register_catalog_meta_boxes' );


function product_data_visibility( $post ) {

    $thepostid          = $post-ID;
    $product_object     = $thepostid ? wc_get_product( $thepostid ) : new WC_Product();
    $current_visibility = $product_object-get_catalog_visibility();
    $current_featured   = wc_bool_to_string( $product_object-get_featured() );
    $visibility_options = wc_get_product_visibility_options();
    ?
div class=misc-pub-section id=catalog-visibility
    ?php esc_html_e( 'Catalog visibility:', 'woocommerce' ); ?
    strong id=catalog-visibility-display
        ?php

        echo isset( $visibility_options[ $current_visibility ] ) ? esc_html( $visibility_options[ $current_visibility ] ) : esc_html( $current_visibility );

        if ( 'yes' === $current_featured ) {
            echo ', ' . esc_html__( 'Featured', 'woocommerce' );
        }
        ?
    /strong

    a href=#catalog-visibility
       class=edit-catalog-visibility hide-if-no-js?php esc_html_e( 'Edit', 'woocommerce' ); ?/a

    div id=catalog-visibility-select class=hide-if-js

        input type=hidden name=current_visibility id=current_visibility
               value=?php echo esc_attr( $current_visibility ); ? /
        input type=hidden name=current_featured id=current_featured
               value=?php echo esc_attr( $current_featured ); ? /

        ?php
        echo 'p' . esc_html__( 'This setting determines which shop pages products will be listed on.', 'woocommerce' ) . '/p';

        foreach ( $visibility_options as $name = $label ) {
            echo 'input type=radio name=_visibility id=_visibility_' . esc_attr( $name ) . ' value=' . esc_attr( $name ) . ' ' . checked( $current_visibility, $name, false ) . ' data-label=' . esc_attr( $label ) . ' / label for=_visibility_' . esc_attr( $name ) . ' class=selectit' . esc_html( $label ) . '/labelbr /';
        }

        echo 'br /input type=checkbox name=_featured id=_featured ' . checked( $current_featured, 'yes', false ) . ' / label for=_featured' . esc_html__( 'This is a featured product', 'woocommerce' ) . '/labelbr /';
        ?
        p
            a href=#catalog-visibility
               class=save-post-visibility hide-if-no-js button?php esc_html_e( 'OK', 'woocommerce' ); ?/a
            a href=#catalog-visibility
               class=cancel-post-visibility hide-if-no-js?php esc_html_e( 'Cancel', 'woocommerce' ); ?/a
        /p
    /div
/div
?php
}

But I am getting issues with server Overload after adding this to my function.php With this Error while trying to publish anything. - Publishing failed. The response is not a valid JSON response.

Anyone Knows the reason...I really need help