app-odoo/app_odoo_customize/static/src/xml/customize_user_menu.xml

<?xml version="1.0" encoding="UTF-8"?>
<templates xml:space="preserve">
    <!--owl 处理继承继承-->
    <t t-inherit="web.UserMenu" t-inherit-mode="extension" owl="1">
        <xpath expr="//td[hasclass('client-line-email')]" position="after">
            <t t-jquery="a[data-menu='documentation']" t-operation="before">
                <switch-lang/>
                <a role="menuitem" href="#" data-menu="debug" class="dropdown-item">Activate the developer mode</a>
                <a role="menuitem" href="#" data-menu="debugassets" class="dropdown-item">Activate the developer mode (with assets)</a>
                <a role="menuitem" href="#" data-menu="quitdebug" class="dropdown-item">Deactivate the developer mode</a>
                <div role="separator" class="dropdown-divider"/>
                <a role="menuitem" href="#" data-menu="documentation_dev" class="dropdown-item">Developer Manual</a>
            </t>
        </xpath>
    </t>
</templates>