How to embed an Amazon script in a post

How can I embed an Amazon Native Ad like this in a Ghost card?

<script type="text/javascript">
amzn_assoc_tracking_id = "internetbo00a-20";
amzn_assoc_ad_mode = "manual";
amzn_assoc_ad_type = "smart";
amzn_assoc_marketplace = "amazon";
amzn_assoc_region = "US";
amzn_assoc_design = "enhanced_links";
amzn_assoc_asins = "160888192X";
amzn_assoc_placement = "adunit";
amzn_assoc_linkid = "9cb76799d4f9d836dcfe949861770685";
<script src="//"></script>

You can try adding it to the post header or footer or as an HTML card.