Every electronic health card (eGK) has its own PIN and PUK. If you receive a new eGK, you will also need a new PIN/PUK letter.
If the registration in the e-prescription app does not work with the PIN for your electronic health card (eGK) that was sent to you, it may be because your PIN/PUK letter was for an older eGK. In this case, you must contact your health insurance company. You will then first be issued with a new eGK, after which you will receive the new PIN and a new PUK. For data protection reasons, your health insurance provider does not know your PIN or the associated PUK. How exactly the ordering process for a new eGK works and what form of identification is required differs depending on the health insurance company. You can get more information about this directly from your health insurance company.