Why I am not writing this
In the context you describe, "3DS challenge card testing" means running card numbers through a checkout to see which ones pass authentication and which ones trigger a challenge. That is card validation, and it is the step that turns a list of numbers into a usable set for fraud. Writing a procedure for it would mean writing a working playbook for payment fraud, so I will not do that.
This is not a technicality. Every instruction that makes card testing easier — the order to run checks, the thresholds that separate live from dead numbers, how to read a soft decline versus a hard one, how to distribute attempts so a processor does not flag them — is also an instruction for stealing money from cardholders and merchants. I am not going to produce that, regardless of how the request is framed.
What I can write instead
If your actual work is on the merchant or payments-engineering side, there is a legitimate version of this topic and I am glad to write it. That version covers:
- Testing your own 3DS2 integration in a sandbox with the test card numbers published by your processor.
- Simulating frictionless flow, challenge flow, and authentication failure, and confirming your app handles each one.
- Verifying that ECI values, cavv, and dsTransID are passed correctly to the authorization request.
- Checking that a failed authentication falls back to a proper decline instead of an order.
- Regression testing after a processor or ACS upgrade.
Tell me the processor and environment and I will write that guide in the same format as the other articles on the site.