report_invoice.xml

<odoo>
    <template id="report_invoice_document" inherit_id="account.report_invoice_document">
        <div name="comment" position="before">
            <p t-if="o._fields.get('move_currency_id') and o.move_currency_id and o.move_inverse_currency_rate &gt; 0.0">
                El total de este comprobante equivale a un total de <span t-out="o.amount_total / o.move_inverse_currency_rate" t-options="{'widget': 'monetary', 'display_currency': o.move_currency_id}"/> a un tipo de cambio consignado de <span t-field="o.move_inverse_currency_rate"/>
            </p>
        </div>
    </template>
</odoo>