pos/pos_order_return_traceability/static/src/xml/pos.xml

<?xml version="1.0" encoding="UTF-8"?>
<templates id="template" xml:space="preserve">

    <t t-extend="OrderLine">
        <t t-jquery=".button.order-list-return" t-operation="attributes">
            <attribute name="t-if">widget.pos.config.iface_return_done_order and order.is_returnable</attribute>
        </t>
    </t>

</templates>