How to use ransack search to search association

i want to search products which are belonging to categories (saree, salwar).

i have the controller like this

class SearchController < ApplicationController def index q = params[:q] @key = q @products = Product.ransack(name_or_description_or_sku_or_category_id_in_cont: q).result(distinct: true).page(params[:page]).per(6) end end here it is selecting name description and sku , but categoty is not searching. hoe to do it in ransack?

my model is like this

product.rb belongs_to :category

category.rb has_many :products

in my product table fields include(name,description,image,category_id,sku)

please give a solution for this