widget.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<widgets xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Widget:etc/widget.xsd">
    <widget id="sales_widget_guestfrom" class="Magento\Sales\Block\Widget\Guest\Form" is_email_compatible="true">
        <label translate="true">Orders and Returns</label>
        <description translate="true">Orders and Returns Search Form</description>
        <parameters>
            <parameter name="title" xsi:type="text" visible="false">
                <label translate="true">Anchor Custom Title</label>
            </parameter>
            <parameter name="template" xsi:type="select" visible="true" required="true">
                <label translate="true">Template</label>
                <options>
                    <option name="default_template" value="widget/guest/form.phtml">
                        <label translate="true">Default Template</label>
                    </option>
                </options>
            </parameter>
        </parameters>
        <containers>
            <container name="sidebar.main">
                <template name="default" value="default_template" />
            </container>
            <container name="sidebar.additional">
                <template name="default" value="default_template" />
            </container>
        </containers>
    </widget>
</widgets>