L8-end updateVariant method need to add "this.onSale = this.variants[index].quantity" to change onSale property ?

[mako4kamiya]

        updateVariant(index) {
            this.selectedVariant = index
        }

        updateVariant(index) {
            this.selectedVariant = index
            **this.onSale = this.variants[index].quantity**
        }