create_job.rb

class OrdersCreateJob < ActiveJob::Base
  queue_as :default

  def perform(json)
    order = Order.create(order_data: json)

    product_ids = []

    json['line_items'].each do |line_item|
      product_ids << line_item['product_id']
    end

    products = DesignersProduct.where(product_id: product_ids)
    products.each do |product|
      designer = Designer.find(product.designer_id)
      OrderMailer.order_details_email(designer).deliver_now

      @template = EmailTemplate.find(1)
      OrderNotification.create(to: designer.name, subject: @template.subject, message: @template.body)
    end
  end
end

webhooks_controller.rb

class WebhooksController < ApplicationController
  def orders_create
    json = ActiveSupport::JSON.decode(params.to_json)
    OrdersCreateJob.perform_later(json)
    
    head :ok
  end
end