Does the certificate expire? How do I renew it?

Yes: it is valid for 24 months from its issuance. The reason is simple: typing speed changes with practice, and a certificate from five years ago doesn’t say much about how you type today.

To renew it, you take the exam again. It is the same process and the same price, and you get a new certification with your current score, which will very likely be better.

While it is active, your certificate remains verifiable on its public page, with its validity date visible.

An expired certificate does not disappear: the verification page still exists and shows that it expired. You will never lose proof of having obtained it.