How can I render an html view with register_rest_route

https://developer.www.ads-software.com/rest-api/extending-the-rest-api/routes-and-endpoints/#routes-vs-endpoints

Endpoints are functions available through the API.
A route is the “name” you use to access endpoints, used in the URL.

https://developer.www.ads-software.com/rest-api/requests/

the REST API is designed to be used remotely over HTTP. HTTP is the foundation for communication of data over the internet, and any application capable of HTTP requests may make use of the WordPress REST API, whether that application is a client-side JavaScript interface or an application on a remote server running in Python or Java.

https://developer.www.ads-software.com/rest-api/extending-the-rest-api/adding-custom-endpoints/

https://developer.www.ads-software.com/reference/functions/register_rest_route/