web/web_notify/views/web_notify.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <template id="assets_backend" name="web_noify assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <link rel="stylesheet" href="/web_notify/static/src/css/notification.less"/>
                <script type="text/javascript" src="/web_notify/static/src/js/web_client.js"/>
                <script type="text/javascript" src="/web_notify/static/src/js/notification.js"/>
            </xpath>
        </template>
    </data>
</odoo>