pos/pos_partner_firstname/static/src/xml/pos.xml

<?xml version="1.0" encoding="UTF-8"?>
<templates id="template" xml:space="preserve">

    <t t-extend="ClientDetails">
        <t t-jquery=".client-name" t-operation="after">
            <div class="client-details-box clearfix">
                <div class="client-detail">
                    <span class='label'>Company</span>
                    <input type='checkbox' class='detail is_company' name='is_company'
                           t-att-checked="partner.is_company ? 'checked' : null" disabled="disabled"
                           t-att-value="partner.is_company"/>
                </div>
            </div>
        </t>
        <t t-jquery=".client-details-left" t-operation="prepend">
            <t t-if="partner.is_company == false">
                <div t-attf-style="display: #{!partner.is_company ? 'block': 'none'};">
                    <div class="client-detail">
                        <span class='label'>First Name</span>
                        <span class='detail firstname'><t t-esc='partner.firstname or ""'/></span>
                    </div>
                </div>
            </t>
        </t>
        <t t-jquery=".client-details-right" t-operation="prepend">
            <t t-if="partner.is_company == false">
                <div t-attf-style="display: #{!partner.is_company ? 'block': 'none'};">
                    <div class="client-detail">
                        <span class='label'>Last Name</span>
                        <span class='detail lastname'><t t-esc='partner.lastname or ""'/></span>
                    </div>
                </div>
            </t>
        </t>
    </t>

    <t t-extend="ClientDetailsEdit">
        <t t-jquery=".client-name" t-operation="append">
            <div class="client-details-box clearfix">
                <div class="client-detail">
                    <span class='label'>Company</span>
                    <input type='checkbox' class='detail o_checkbox checkbox is_company'
                           name='is_company' t-att-checked="partner.is_company ? 'checked' : null"
                           t-att-value="partner.is_company"/>
                </div>
            </div>
        </t>
        <t t-jquery=".client-details-left" t-operation="prepend">
            <div class="is_person" t-attf-style="display: #{!partner.is_company ? 'block': 'none'};">
                <div class='client-detail'>
                    <span class='label'>First Name</span>
                    <input class='detail firstname person' name="firstname" t-att-value='partner.firstname or ""'/>
                </div>
            </div>
        </t>
        <t t-jquery=".client-details-right" t-operation="prepend">
            <div class="is_person" t-attf-style="display: #{!partner.is_company ? 'block': 'none'};">
                <div class='client-detail'>
                    <span class='label'>Last Name</span>
                    <input class='detail lastname person' name="lastname" t-att-value='partner.lastname or ""'/>
                </div>
            </div>
        </t>
    </t>

</templates>