purchase_request_demo.xml

<?xml version="1.0" encoding="utf-8" ?>
<!-- Copyright 2018-2019 ForgeFlow, S.L.
     License LGPL-3.0 or later (http://www.gnu.org/licenses/lgpl-3.0) -->
<odoo noupdate="1">
    <record id="base.user_demo" model="res.users">
        <field eval="[(4, ref('group_purchase_request_user'))]" name="groups_id" />
    </record>
    <record id="base.user_admin" model="res.users">
        <field eval="[(4, ref('group_purchase_request_manager'))]" name="groups_id" />
    </record>
</odoo>