Odoo-Build/snippets/account.report_invoice_document.custom_payment_term.xml

<data inherit_id="account.report_invoice_document" priority="50">
    <xpath expr="//p[@name='payment_term']" position="replace">
        <p t-if="o.invoice_payment_term_id" name="payment_term">
      Payment terms: <strong t-field="o.invoice_payment_term_id.name"/>
    </p>
    </xpath>
</data>
<!-- Version 16
<data inherit_id="account.report_invoice_document" priority="50">
    <xpath expr="//div[@name='payment_term']" position="replace">
        <p t-if="o.invoice_payment_term_id" name="payment_term">
      Payment terms: <strong t-field="o.invoice_payment_term_id.name"/>
    </p>
    </xpath>
</data>
-->