The script tag is the product. The plugins are a convenience.
It is worth being clear about this, because plenty of chat tools make installation sound like an integration project. It is not one. The widget is a single JavaScript file. You load it, you tell it which agent to run, and it renders. That is the whole mechanism, and it is the same mechanism on every platform.
Nothing about this product requires a plugin. If you can paste a line of HTML into your site, you are done, whether that site is a Shopify theme, a Webflow project, a Next.js app or a page somebody hand-wrote in 2011.
The plugins exist for a narrower reason: on some platforms, pasting a script tag means editing a theme file, and the person who wants the chat widget is not the person with access to the theme file. The plugin removes that step.
Nothing about this product requires a plugin. One script tag before the closing body tag installs the widget on any site.