Adding JS tracking link

Hello,

I have a tracking link from a 3rd party that I need to add on my websites. When I go into code injection to place the script, it doesn't save for either the header or the footer. Is this an issue with my squarespace or the script?

Please see below for the tracking script.

<script type="text/javascript" src="//realtyads.com/px/4210"></script>

Hi , your script seems fine , Will you please let us know which Squarespace Subscription Plan you are using as to use code injection you need at least Business Plan.