Form Code Breaking Site Editor

Site URL: https://coyote-recorder-ae53.squarespace.com/

Hi! So I'm trying to add a line of code for my email signup form, however whenever I do the code breaks the editor so to speak and I can't open up the editor outside of safe mode. It also prevents images from showing on the site. Here is the code I'm trying to add: <script type='text/javascript' src='https://app.getresponse.com/view_webform_v2.js?u=trKMf&webforms_id=zzgFm'></script>

Site password is: red

Here is a video I got from Squarespace support showing the issue: https://share.squarespace.com/nOuXDxDe

Thanks so much!

Have you asked Get Response if their code is compatible with SS? I only saw mention of WordPress and Facebook.