Попробуйте в файле
design/themes/TEMA/templates/views/checkout/components/payments/checkout.tpl
заменить
{if $auth.act_as_user}
<div class="ty-control-group">
<label>
<input type="checkbox" id="skip_payment" name="skip_payment" value="Y"
class="checkbox"
/>
{__("skip_payment")}
</label>
</div>
{/if}
на
<div class="ty-control-group">
<label>
<input type="checkbox" id="skip_payment" name="skip_payment" value="Y"
class="checkbox"
/>
{__("skip_payment")}
</label>
</div>