In many live environments, customers handle all incoming orders the same way; whether they come from a regular user of their site or from a tester testing the checkout process. In that case, purchases/bookings on these live environments will cause a lot of trouble for our customers:
The customer will try to ship the order. This may or may not be successful, but in either case, it requires manual work from their side to cancel these orders.
Canceled orders will negatively affect the customer's sales metrics and conversion rates.
For order attempts but especially completed orders, the customer may even have to pay fees to the payment provider that was used. This means extra, unnecessary costs on the customer side without any value.
These are reasons why we need to prevent any order submissions as well as attempts to place orders on most live environments.
As for order attempts, when you are asked to select a payment method, you should be alerted:
Be cautious what you do on the payment selection page or the payment selection modal.
Stay away from buttons that are labeled Continue to PayPal, PayPal Express, or Amazon Express. Clicking on any of them usually initiates the first step of a payment process already.
Take your time to read through everything on that page and read all button labels. Any button to continue the checkout process after selecting a payment method can start the payment process.
When you reach the last step of the checkout process, stop testing on the final checkout page. Leaving the page is the safest way to prevent order submissions.
Do not click on the button that finalizes the order, which is often called Complete order, Finish order, Complete purchase, Complete booking, etc.
Do not submit the order form with blank mandatory fields. This can easily go wrong and can actually submit the order.
If you are not uncertain whether or not you should click on a given button, rather stay away from the button and don't click on it. You can ask the Team Leader of your test for guidance in the Test Chat if you have any questions.
Do not complete any purchases and do not place any orders.