pos/pos_order_remove_line/static/src/xml/order_line.xml

<!--
  ~ Copyright 2019 LevelPrime
  ~ License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
  -->

<templates id="template" xml:space="preserve">
    <t t-extend="Orderline">
        <t t-jquery=".price" t-operation="before">
            <button class="remove-line-button">
                <i class="fa fa-trash-o"/>
            </button>
        </t>
    </t>
</templates>