Odoo-Build/snippets/stock.report_delivery_document.barcode_customer_reference.xml

<data inherit_id="stock.report_delivery_document" priority="50">

  <xpath expr="//h2" position="before">
    <span t-field="o.sale_id.client_order_ref" t-options="{&quot;widget&quot;: &quot;barcode&quot;, &quot;width&quot;: 350, &quot;height&quot;: 50}"/>
  </xpath>

</data>