You can find your purchase receipt in the Tommy's Express app under "Billing". From there, you can download it as a PDF or enter an email address to send it to.
Your receipt will provide your purchase amount, including any discounts, which plates were paid for, and your wash period.
Under 'Account Details', tap on the pencil 'edit' icon, and use the toggle to adjust your preferences for Email Receipts. When toggled on, you will be emailed a receipt automatically after every payment.