Is there a way to do user tasks thru the REST API?

Seems the user tasks have to go thru the Admin interface.
Can I make an API call to get the form and respond back?

Also, if I reach a decision gateway, can the API return back the choices?

Is there a tutorial with more REST API calls? The API is well documented, but seeing which calls meet needs is a bit challenging.

Thanks.

@lenny_h you can achieve the same via rest api.

Go through this task rest api docs https://docs.camunda.org/manual/7.11/reference/rest/task/