How and what parameters should be passed to the form if the route is nested?

Question

Ruby on Rails

Good evening.
There is a user, a comment model has been added to the user, all associations are spelled out correctly, the route is nested (comments are nested in the jureza).
When creating a form - writes the method does not exist.
I write like this:

<%= form_for ([@user, @user.comments.build])  do |f| %>
  <%= f.label :body %>
  <%= f.text_field :body %>
  <%= f.text_field :user_id %>
  <%= f.submit' %>
<% end %>

In the comment controller, this is the code:

@user = User.find(params[:user_id])
    @comment = @user.comments.create(send_params)

I understand that in the form we need to pass the user as the first parameter and the second as a way to indicate that this user has an association with comments.
Am I wrong somewhere?

Answer 1

What mistake? What's in the new comment controller? How defined routes? Why does the submit button have an extra quote in the form? )
<%= f.submit' %>

Answer 2

Can be in the form to specify simply the user and object of the comment?
Because in the controller you still create it directly through the user.
Well, this is just a guess, I myself don’t shine with experience yet, but on such questions, additional experience is filled just right.
And what for in the form this field? If to get the user in the controller, then he will come in the same way in the parameters. <%= f.text_field :user_id %>