template_view.xml

<?xml version="1.0" encoding="utf-8"?>

<odoo>
    <data>
        <template id="assets_backend" name="school assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <link rel="stylesheet" href="/school/static/src/scss/schoolcss.scss"/>
            </xpath>
        </template>
    </data>
</odoo>