discourse-subscriptions/assets/javascripts/discourse/routes/user-billing-payments.js

import Route from "@ember/routing/route";
import UserPayment from "discourse/plugins/discourse-subscriptions/discourse/models/user-payment";

export default class UserBillingPaymentsRoute extends Route {
  templateName = "user/billing/payments";

  model() {
    return UserPayment.findAll();
  }
}