add new table

db/migrate/20191203014808_create_subscriptions_customers.rb

@@ -0,0 +1,10 @@
+class CreateSubscriptionsCustomers < ActiveRecord::Migration[6.0]
+  def change
+    create_table :discourse_subscriptions_customers do |t|
+      t.string :customer_id, null: false
+      t.string :product_id
+      t.references :user, foreign_key: true
+      t.timestamps
+    end
+  end
+end