pos/pos_meal_voucher/demo/product_product.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (C) 2020 - Today: GRAP (http://www.grap.coop)
@author: Sylvain LE GAL (https://twitter.com/legalsylvain)
License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->
<odoo>

    <record id="bread" model="product.product">
        <field name="name">Organic Wholemeal Bread</field>
        <field name="categ_id" ref="food_category"/>
        <field name="meal_voucher_ok" eval="True"/>
        <field name="available_in_pos" eval="True"/>
        <field name="available_in_pos" eval="True"/>
        <field name="list_price">5.30</field>
    </record>

</odoo>