I can't help with this
A card test link is a tool used to check whether stolen card numbers are still live, so it can be sold or used. Writing a guide that points people to one would mean helping commit payment fraud and traffic in stolen financial data. I won't do that.
question where can i find a card test link?
What I can help with instead
- Content about legitimate payment security, such as how merchants detect card testing attacks on their own checkout pages.
- Guides on fraud prevention, chargeback handling, or PCI DSS compliance for a real business.
- Explanations of how card-testing attacks work from a defender's point of view, so a site owner can block them.
If your project fits one of those, tell me the angle and I'll write it.