I am implementing 2checkout payment gateway on my website. After testing (sandbox mode), I failed to see any transaction on 2checkout dashboard after testing on my website.
Sandbox sales will only be visible in your 2Checkout sandbox admin area. In your sandbox admin you can click on the "Sales" tab to view all of your sandbox sales. Please reach out to 2Checkout tech support at techsupport@2co.com if you would like further assistance with your sandbox testing.