Hi there! I see you're encountering "Error 21" while setting your PIN in the PBZ Card MyWay app. Let's get this sorted out for you.

To start, could you tell me a bit more about when exactly this error appears? For example, is it right after you enter your desired PIN, or during the confirmation step? Also, have you tried setting the PIN before, or is this your first attempt?

Meanwhile, here are some initial steps that often help with PIN setting issues in the app:

1. Ensure the app is fully updated: Sometimes, errors come up if the app version is outdated. Go to your app store and check if there's an update for PBZ Card MyWay.

2. Check your internet connection: A stable internet connection is required for PIN setup. If you're on Wi-Fi, try switching to mobile data or vice versa.

3. Restart the app and your device: Close the PBZ Card MyWay app entirely, then restart your computer or device and try again.

4. Clear app cache and cookies (if applicable): Since you're on a Windows device using WebKit browser, clear your browser's cache to remove any corrupted session data.

5. Confirm your registration and card activation: Sometimes PIN errors arise if your card or account registration isn't fully completed. Verify your registration status in the app or on the PBZ Card website.

If you’ve already done any of these, please let me know so I can guide you to the next steps.

Also, sometimes "Error 21" could indicate a server-side issue or temporary service interruption. If the problem persists, we might need to check if there are any known outages or escalate to support.

Please give these a try and share what happens, so I can assist you further!