How to create a programmatically variable product?

Question

WordPress

Greetings!
Just don't send it to Google right away, please.
I tried a hundred ways to make variations in WooCommerce programmatically - it doesn't work.
Please help!

// In a class constructor
        $this->brand_tax = wc_attribute_taxonomy_name( 'brand' );
        // Insert the main product first
        // It will be used as a parent for other variations (think of it as a container)
        // Insert the attributes (I will be using size and color for variations)
        $attributes = array(
            $this->brand_tax => array(
                'name' => $this->brand_tax,
                'value' =>'',
                'is_visible' => '1',
                'is_variation' => '1',
                'is_taxonomy' => '1'
            )
        );
        update_post_meta( $new_id, '_product_attributes', $attributes );
        // Assign sizes and colors to the main product
        wp_set_object_terms( $new_id, array( 'OFM', 'ITR' ), $this->brand_tax );
        // Set product type as variable
        wp_set_object_terms( $new_id, 'variable', 'product_type', false );
        $parent_id = $new_id;
        $variation = array(
            'post_title'   => 'Product #' . $parent_id . ' Variation',
            'post_content' => '',
            'post_status'  => 'publish',
            'post_parent'  => $parent_id,
            'post_type'    => 'product_variation'
        );
        // The variation id
        $variation_id = wp_insert_post( $variation );
        // Regular Price ( you can set other data like sku and sale price here )
        update_post_meta( $variation_id, '_regular_price', 2 );
        update_post_meta( $variation_id, '_price', 2 );
        // Assign the size and color of this variation
        update_post_meta( $variation_id, 'attribute_' . $this->brand_tax, 'OFM' );
        // Update parent if variable so price sorting works and stays in sync with the cheapest child
        WC_Product_Variable::sync( $parent_id );

Here is the last one I tried.
The product does not even want to become variable ..