It's works!! Thanks!!!

Thanks for your response. After retesting with different incorrect passcode, the devices were wiped.

Your code really helped me a lot! When I add 'kSecAttrAccessGroup as String: "com.apple.managed.vpn.shared"' to the query parameters, I always get a -50 error. This issue has troubled me for a long time, and I didn't realize that this parameter could be ignored.