discourse/plugins/discourse-subscriptions/assets/javascripts/discourse/discourse-subscriptions-user-route-map.js

export default {
  resource: "user",
  path: "users/:username",
  map() {
    this.route("billing", function () {
      this.route("payments");
      this.route("subscriptions", function () {
        this.route("card", { path: "/card/:stripe-subscription-id" });
      });
    });
  },
};