This code works in other versions but in the 14 version there is no change.

<?xml version="1.0" encoding="UTF-8"?>
    <templates id="template" xml:space="preserve">
        <t t-extend="PaymentScreen">
            <t t-jquery="[class='payment-buttons']" t-operation="after">
                <section class="convert-enable-section">
                    <label class="switch">
                      <input type="checkbox" id="enable_convert" name="enable_convert"/>
                      <span class="slider"></span>
                    </label>
                    Enable conversion
                </section>
            </t>
        </t>
    </templates>