Email PopUp doesn’t work on thank you page

Hi, my pop up forms work perfectly everywhere other than checkout and thank you / order received page.

I read a post that the code doesn’t run on the checkout page by default, which is fine, I’m not too worried about that, but it said to show a legacy form instead to counteract this.

Is this also the case for the thank you page? If so, how can I add the code to the thank you page? I’ve been trying to do this and can’t work it out. I am using the default Klaviyo code and it works on other pages so I know it’s right, I just don’t know how to get it onto the thank you page if that makes sense. This is the code:

<script type="text/javascript" 
src="//www.klaviyo.com/media/js/public/klaviyo_subscribe.js"></script>
<script type="text/javascript">
KlaviyoSubscribe.attachModalSignUp({
 list: '[LIST ID]', delay_seconds: 1,
 content: { clazz: ' klaviyo_modal',
 header: "Interested in our Newsletter?",
 subheader: "Stay in the know with news and promotions.",
 button: "Subscribe", success: "Thanks! Check your email for a confirmation.",
 styles: '.klaviyo_modal { font-family: "Helvetica Neue", Arial}.klaviyo_modal .klaviyo_header { color:#222;}.klaviyo_modal .klaviyo_subheader { color:#222;}.klaviyo_modal .klaviyo_submit_button,.klaviyo_modal .klaviyo_submit_button span { background-color:#0064CD; background-image: none; border-radius: 2px;}.klaviyo_modal .klaviyo_submit_button:hover,.klaviyo_modal .klaviyo_submit_button span:hover { background-color:#0064CD; background-image: none; }.klaviyo_modal .klaviyo_inner,.klaviyo_modal .klaviyo_fieldset .klaviyo_field_group input[type=text],.klaviyo_modal .klaviyo_fieldset .klaviyo_field_group input[type=email] { border-radius: 2px;}'
 }
});
</script>

Thanks in advance!