Is it possible to run the php script of the merchant separately from the entire backend of the online store in JS?

Question

PHP

I am considering the possibility of connecting one merchant to my online store. But here a complication arose.
The fact is that I do not use any CMS, but do everything on JS and static HTML (there are few goods, no database is needed). And the merchant offers ready-made solutions only for popular PHP CMS. But it's okay if it was one problem.
Another solution is his PHP script + HTML form. And here I have difficulties, because I did not come across PHP in practice, I only raised the PHP server on a PC under Wordpress a couple of times (I have little experience in coding at all, so I ask for help).
Can I run this PHP merchant script separately from my entire site, ON A COMPLETELY DIFFERENT SERVER? And on your site, just embed this form in your markup. And filling out this form, the user will send data to the server where this PHP script is, and then...

Answer 1

1. If the merchant script checks the domain, then definitely: NO.
2. It is better to ask this question to the merchant, whose script you are going to install in such an "interesting" way.
In general, I advise you to do it right.
PS: If you don't know something, there is always freelancing.

Answer 2

Not sure if I understood you correctly, but maybe an iframe? Although in fact the design turns out to be really strange, I think everything can be simplified somewhat. For example, why another server with php scripts? You can also place it on one server and simply add this form to your site.