How to get Checkbox value in ruby on rails

I want to get checkboxs values in order to set parameters of an http request to a restful API. I am new to web development and I am having troubles with ruby on rails 5.1

Basically, I have two views: - one where you can check/uncheck two checkboxs and then press a button which makes some API calls and send you to the second view. - the second is just for displaying the API informations.

In the first view, I succeed to do the button that "makes" the API call, and the API informations are correctly displayed in the second. I now have trouble to add parameters, with the two checkboxs, to the request. My checkboxs are always returning me "nil" in params[].

I referred to this section of the rails doc: https://guides.rubyonrails.org/form_helpers.html#helpers-for-generating-form-elements and to several other stackoverflow questions without understanding what I missed.

here is the controller code:

class IndexController < ApplicationController
  include HTTParty

  def button_state
  end

  def display_state
    require 'open-uri'
    require 'json'

    # this part is for checking my checkbox values, they are always nil

    @t1 =  params[:param_name1]
    @t2 =  params[:param_name2]
    @url_test = 'www.bkbahbqiv.com/tamere?test1=' << @t1.to_s << '&test2=' << @t2.to_s

    # other part related to the API calls
    ...
  end
end

and here is my view code:

<h1>Check/Uncheck the boxes and click on the button to get results</h1>
<div class="checkbox">
  <td>
  <%= label_tag(:param_name1, "test1") %>
  <%= check_box_tag(:param_name1) %>
  </td>
</div>
<div class="checkbox">
  <td>
  <%= label_tag(:param_name2, "test2") %>
  <%=  check_box_tag(:param_name2) %>
  </td>
</div>

<%= button_to "go to display_state", display_state_path, :method => :get %>

I will just add that I don't want to store the checkbox values in a database.

Thanks in advance for anyone helping me :)