pos/barcodes_generate/demo/res_users.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (C) 2016-Today: GRAP (http://www.grap.coop)
Copyright (C) 2016-Today GRAP (http://www.lalouve.net)
@author Sylvain LE GAL (https://twitter.com/legalsylvain)
License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
-->

<odoo>

    <record id="base.user_root" model="res.users">
        <field name="groups_id" eval="[
            (4, ref('barcodes_generate.generate_product_barcode')),
            (4, ref('barcodes_generate.generate_partner_barcode')),
            (4, ref('product.group_product_variant')),
            ]" />
    </record>

</odoo>