account-financial-tools/account_permanent_lock_move/views/res_config_view.xml

<odoo>
    <record id="view_account_config_settings_permanent_lock" model="ir.ui.view">
        <field name="name">account settings permanent lock</field>
        <field name="model">account.config.settings</field>
        <field name="inherit_id" ref="account.view_account_config_settings"/>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='fiscalyear_lock_date']/parent::div" position="after">
                <div>
                    <label for="permanent_lock_date"/>
                    <field name="permanent_lock_date" readonly="1"/>
                </div>
                <div>
                    <button type="object" name="change_permanent_lock_date" string="Permanently Lock Entries" class="btn-primary"/>
                </div>
            </xpath>
        </field>
    </record>
</odoo>