odoo16/addons/hr_holidays/wizard/hr_holidays_cancel_leave_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="hr_holidays_cancel_leave_form" model="ir.ui.view">
        <field name="model">hr.holidays.cancel.leave</field>
        <field name="arch" type="xml">
            <form string="Cancel Time Off">
                <group>
                    <field name="leave_id" invisible="1" />
                    <field name="reason" placeholder="Provide a reason for cancellation of an approved time off" />
                </group>
                <footer>
                    <button name="action_cancel_leave" type="object" class="btn-primary" string="Delete Time Off" />
                    <button special="cancel" string="Discard" close="1" />
                </footer>
            </form>
        </field>
    </record>
</odoo>