web/support_branding/static/src/xml/base.xml

<?xml version="1.0" encoding="UTF-8"?>
<templates>
    <t t-extend="CrashManager.error">
        <t t-jquery="div" t-operation="after">
            <div>
                <form class="support-branding-submit-form oe_form" action="mailto:" enctype="text/plain" method="get">
                    <input type="hidden" name="subject" t-attf-value="#{session.username}@#{session.db} [#{session.server}]: #{error.message}" />
                    <input type="hidden" name="body" t-attf-value="#{error.data.debug}" />
                    <div class="oe_form_field_text oe_form_required">
                        <textarea name="description" placeholder="Please fill in how you produced this error..." class="" />
                    </div>
                    <button class="btn btn-sm oe_button btn-primary">Email to support company</button>
                </form>
            </div>
        </t>
    </t>
</templates>