stripe-react-serverless-29.ts

class StripeManager {
  ...

  public static async getStripeCustomerID() {
    // Retrieve the current customerID from the currently logged in user
    // getUserFromDB() is *your* implemention of getting user info from the DB
    const { customerID } = getUserFromDB();

    if (!customerID) {
      const customer = await this.createCustomer();
      return customer?.id;
    }

    return customerID;
  }

  ...
}