whatsapp_web_groups/data/ir_cron.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo noupdate="1">

    <record id="ir_cron_sync_ww_contacts_groups" model="ir.cron">
        <field name="name">Sincronizar Contactos y Grupos WhatsApp Web</field>
        <field name="model_id" ref="model_ww_group"/>
        <field name="state">code</field>
        <field name="code">model.sync_ww_contacts_groups()</field>
        <field name="interval_number">1</field>
        <field name="interval_type">hours</field>
        <field name="active" eval="False"/>
    </record>
    
</odoo>