Maybe you can try to build at first a web application with express. Of course you can create a web app without express if you need it. With express and Node.js I created a MySQL REST API. With HTML and Ajax you can fetch the Data from the API. So you can create two applications. One application where you need to run Node.js because it`s much easier to create a REST API with express. The second one is fully without Node.js.
Maybe there are better solutions, but inside each Web Application you can than but you can then access this API in any web application using jQuery. It doesn't matter if it is written with PHP, ASP.Net Core, Java EE / EE4J. You can also access this API in Ruby, Angular, React, Vue etc. using an AJAX request.
In some scenarios you can't start Node.js as a server because an application is already running on apache2 or nginx. There this would be a workaround to use something like this. For example, one could also integrate applications with HTML+JS in a CMS system that accesses other database tables and thus extend such a system without an iframe.
So can be helpful for few scenarios. Now just doesn't get around the actual goal of doing without Node.js completely or even express. But why are there REST APIs? So that you can query the data and incorporate it somewhere else. Otherwise you would have to build a REST API with another technology. Especially in the example of accessing MySQL with JavaScript, this would not be quickly feasible.
If you are looking for a similar solution to separate the web app and the REST API, but you don't need Node.js, then you should really build a REST API with .Net Core or with another technology, depending on what is possible and installed on your server. It could be Java or PHP behind it or Ruby.
The API that provides the REST access does not have to be written in JavaScript. You only need to be able to access it with JavaScript. So you can use many different approaches to access JSON data. I hope that in the short time with my bad English I have explained the basic idea, how to proceed stylistically and where advantages exist in REST interfaces.
With this, it should be self-explanatory that you don't have to use NodeJS and Express, but with JavaScript it's a pleasant solution. Only you have to ask yourself if a JavaScript application has to provide this interface at all or if in the end only a JavaScript application has to access this interface. Very big difference.
web frameworkfor node.js which means you need to have access to node. Which other language options are avail in your hosting, I'd suggest python/django/flask