adding search function to my rails API (with pg_search), model comming from external DB, getting Object doesnt support #inspect

Question

i know there are several questions like this one, but this is a bit different since my model is not stored in rails database, it is coming from an external db. I implemented pg_search in the model, like this:

class ExternalProduct < ApplicationRecord
  establish_connection :external_db
  self.table_name = "product"

  include PgSearch::Model
  pg_search_scope :search_by_name,
  against: [ :name ],
  using: {
    tsearch: {prefix: true}
   }

end

the database (in database.yml) is the following:

external_db:
  adapter: mysql2
  database: ****
  username: ****
  password: ****
  host: mdb-test.****.us-west-1.rds.amazonaws.com
  encoding: utf8

but when i type in the rails terminal

ExternalProduct.search_by_name("vodka")

i get the following error:

irb(main):001:0> ExternalProduct.search_by_name("vodka")
  ExternalProduct Load (282.0ms)  SELECT `product`.* FROM `product` INNER JOIN (SELECT `product`.`id` AS pg_search_id, (ts_rank((to_tsvector('simple', coalesce(`product`.`name`::text, ''))), (to_tsquery('simple', ''' ' || 'vodka' || ' ''' || ':*')), 0)) AS rank FROM `product` WHERE ((to_tsvector('simple', coalesce(`product`.`name`::text, ''))) @@ (to_tsquery('simple', ''' ' || 'vodka' || ' ''' || ':*')))) AS pg_search_a8792157cb4f27fb949c03 ON `product`.`id` = pg_search_a8792157cb4f27fb949c03.pg_search_id ORDER BY pg_search_a8792157cb4f27fb949c03.rank DESC, `product`.`id` ASC
(Object doesn't support #inspect)
=>

I would appreciate any advise, since this is a homework for a job interview (first job as a developer) :)