lefilament_account_view.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <!-- Account Invoice Form - Trigger validation  -->
    <record model="ir.ui.view" id="lf_invoice_form">
        <field name="inherit_id" ref="account.invoice_form"/>
        <field name="name">account.invoice.form</field>
        <field name="model">account.invoice</field>
        <field name="arch" type="xml">
            <xpath expr="//button[@name='action_invoice_open']" position="attributes">
                <attribute name="confirm">Do you want to confirm this invoice ?</attribute>
            </xpath>
        </field>
    </record>

    <!-- Customer Account Invoice Tree -->
    <record id="lf_view_invoice_tree" model="ir.ui.view">
        <field name="inherit_id" ref="account.invoice_tree"/>
        <field name="name">account.invoice.tree</field>
        <field name="model">account.invoice</field>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='amount_total_signed']" position="after">
                <field name="amount_untaxed_signed" widget="monetary" sum="Total Untaxed" />
            </xpath>
        </field>
    </record>
</odoo>