If you have Gift terms enabled on your application, it's possible to show a Redeem button in the footer of your Offer templates.
In order to remove it, you would need to go to Manage → Templates and remove the following code from your Offer template:
HTML
<div class="offer-redemption" ng-show="allowRedemption()">
<table>
<tr>
<td class="title">
<t>Did you receive a voucher?</t>
</td>
<td class="choose">
<a
ng-click="startRedemption()"
external-event="piano-checkout-offer-click"
class="button big fixed"
>
<t>Redeem</t>
</a>
</td>
</tr>
</table>
</div>