Hi, i know this is too late but it’s for ones who had same problem and couldn’t figured it out
all the help you need is on this page:
https://thecartpress.com/docs/design-and-layout/extended-template-hierarchy-for-thecartpress/
1- i copied page.php from my theme and renamed it to be: single-tcp_saleable.php (cause thecartpress search for specific templates, and when he find nothing he will write the content on page.php)so now we have created a template for him to put content on it rather than on page.php
2- then i put the content of this page: tcp-single-product.php (which is on theme templates on thecartpress plugin directory, and ut’s the page where single product detail is generated) between code of the new single-tcp_saleable.php page
3- so we have then single-tcp_saleable.php with code from page.php (to be able to put or hide the sidebar and footer)and code from tcp-single-product.php(the core code of product detail page)
when you refresh a product details page on your browser you will have it on the new template you just created, not anymore on page.php
hope this helps, cause i need it too, and this new method wasted me so much time, bit am so happy i figured it out