rma/website_rma/views/website_rma_portal_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2020 Tecnativa - Ernesto Tejeda
     License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). -->
<odoo>
    <template id="portal_my_home_rma" name="Portal My Home : RMA entries" inherit_id="portal.portal_my_home" priority="30">
        <xpath expr="//div[hasclass('o_portal_docs')]" position="after">
            <div class="oe_structure">
                <section class="s_text_block mt16">
                    <div class="container">
                        <div class="row">
                            <div class="col-lg-12 bg-300">
                                <p style="margin-top: 1rem;">
                                    You can request an RMA <strong><a href="/requestrma">here</a></strong> if you do not
                                    know the sales order from which it was made. If you know
                                    the sales order, go to it and click on the corresponding button.
                                </p>
                            </div>
                        </div>
                    </div>
                </section>
            </div>
        </xpath>
    </template>
</odoo>