You mean like this? https://www.rivescript.com/try
It embeds rivescript.js in the web browser and runs all its processing locally. It could use ajax to load the *.rive files and doesn’t need anything special from its back-end server (just a basic Apache setup would work fine for example; friendly with shared hosting providers!)
You’d just download the .zip or .tar.gz of rivescript-js from the Releases page on GitHub: https://github.com/aichaos/rivescript-js/releases
Inside there’s a `dist/` folder containing `rivescript.js` and `rivescript.min.js` (the latter is minified and has a smaller file size, so it should be the one you use “in production”; the other one might help in development because if it raises any errors your browser console can point out the line numbers and be more helpful).
Here’s an example of how to use it (this example loads the *.rive files with ajax): https://github.com/aichaos/rivescript-js/tree/master/eg/web-client