Guidance for implementing Algolia.generate_secured_api_key

index.html.erb

...

$(document).ready(function() {
      var hitTemplate = '<a href="reports/{{{slug}}}" class="hit-report-card">' +
                          '<div id="preview_image" class="hit-report-img" style="content:url(<%= @attachments.find(6).image_url(:preview) %>);">ATTACHMENT ID: {{attachment.id}}</div>' +
                          '<div class="hit-report-title dont-break-out">{{{_highlightResult.title.value}}}</div>' +
                          '<div class="hit-report-date">{{{date_in_words}}}</div>' +
                          '<div class="hit-report-user">{{user.first_name}} {{user.last_name}}</div>' +
                          '<div class="hit-report-type">A/B Test</div>' +
                        '</a>';

      var search = instantsearch({
        appId: '<%= ENV[ 'ALGOLIASEARCH_APPLICATION_ID'] %>',
        apiKey: '<%= ENV['ALGOLIASEARCH_API_KEY_SEARCH'] %>',
        indexName: '<%= Report %>',
        urlSync: true
      });

      search.addWidget(
        instantsearch.widgets.searchBox({
          container: '#q',
          placeholder: 'Search for reports',
          autofocus: false,
          poweredBy: true
        })
      );
      
  ...

Introduction

DISCLAIMER: 
Sorry if this is a little long winded but I just want to ensure I communicate it properly (also I'm still learning Ruby & Rails so sorry if some issues are Rails questions than Algolia specific).

MY APP:
My Rails app has the following models:

- Company (has_many :users, has_many :reports)
- User (belongs_to :company, has_many :reports)
- Report (belongs_to :company, belongs_to :user)

I have managed to successfull indexed my Report model along with some nested attributes as shown below in the report.rb file.

I read this: https://discourse.algolia.com/t/multi-tenant-algolia-index/147 and a few other articals that kind of gave me the impression 
that the best way to multitenancy with Algolia was to add the company_id to the indexed Reports model and then user the generate_secured_api_key
to filter results from the backend so a user only see's their companies reports in the search results.

QUESTIONS:
- Where does public_key = Algolia.generate_secured_api_key 'YourSearchOnlyApiKey', {'filters'=> '_tags:user_42'} go? In my Report model? 
- Do I need to add a migration to my Report model to include a public_key?
- To display Reports where and indexed Report.company_id = current_user.company.id what do I put in the 'filters' section? Or is it not a filter?
- Do I need to change anything in my index.html.erb view to display?

report.rb

...
  
# Algolia Integration - https://www.algolia.com/doc/api-client/rails/usage/
  include AlgoliaSearch

  algoliasearch do
    # all attributes will be sent
    attribute :id, :slug, :title, :overview, :result, :company_id, :user_id, :created_at, :updated_at, :date_in_words

    attribute :user do
      # Adds a nested model for User but restricts to first_name + last_name + email
      { first_name: user.first_name, last_name: user.last_name, email: user.email }
    end

    attribute :attachment do
      # Adds a nested model for Attachment
      { id: attachment_ids }
    end
  end

...