Hi, I managed to get my tag working and catalogue uploaded without turning on developer mode i have now been approved as a verified merchant. Put the base code in the header and the checkout event code in the order confirmation page to navigate to it on squarespace 7,0
settings>advanced>code injection
add the base code in the header section
<!-- PINTEREST TAG BASE CODE -->
<script type="text/javascript">
!function(e){if(!window.pintrk){window.pintrk=function()
{window.pintrk.queue.push(Array.prototype.slice.call(arguments))};var
n=window.pintrk;n.queue=[],n.version="3.0";var
t=document.createElement("script");t.async=!0,t.src=e;var
r=document.getElementsByTagName("script")[0];r.parentNode.insertBefore(t,r)}}
("https://s.pinimg.com/ct/core.js");
pintrk('load','YOUR TAG ID HERE', { em: '{customerEmailAddress}', });
pintrk('page');
</script>
<noscript>
<img height="1" width="1" style="display:none;" alt=""
src="https://ct.pinterest.com/v3/?tid=YOUR TAG ID HERE&noscript=1" />
</noscript>
<!-- END OF PINTEREST TAG BASE CODE -->
Then scroll down to the order confirmation page and put the checkout event code in there
<!-- PINTEREST CHECKOUT EVENT TRACKING -->
<script>
pintrk('track', 'checkout', {
value: 10.00,
order_quantity: 2,
currency: 'GBP',
product_ids: ['1414', '1415'] }
);
</script>
<noscript>
<img height="1" width="1" style="display:none;" alt="" src="https://ct.pinterest.com/v3/?tid=YOUR TAG ID HERE&event=checkout&ed[value]=10.00&ed[order_quantity]=2&noscript=1" />
</noscript>
<!-- END OF PINTEREST CHECKOUT EVENT TRACKING -->
this should get your tag installed but it sometimes takes a few days for the error messages to go away. also if there isn't any activity on your site, the error messages come back. If the tag isn't firing due to lack of activity, pinterest thinks the tag isn't working and so says it's unhealthy. if you're not making many sales, pop a free digital download product in your inventory and go buy it every now and then to make the checkout event fire.
I'm having trouble with my add to cart since it's seems to be firing on every page view. not so worried about that but will try and figure it out.
hope that helps. this is currently working very well for me. happy to help with how i got my verified status if you get your tags working effectively and want it later.