vracoop_website_sale_cart_limit/views/product_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

	<record model="ir.ui.view" id="product_template_form_view">
        <field name="name">product.template.product.coupon.form</field>
        <field name="model">product.template</field>
        <field name="inherit_id" ref="website_sale.product_template_form_view"/>
        <field name="arch" type="xml">
            <div name="options" position="inside">
                <div>
                    <field name="is_coupon"/>
                </div>
            </div>
        </field>
    </record>

</odoo>