If you get an error 3024 message while creating your account, it means that either an account or a user profile is already using this email address. Try using a different email address to finish creating your account.
https://support.withings.com/hc/zh-cn/sections/6216033813649-Withings-App-Android
https://support.withings.com/hc/zh-cn/sections/200608308-Troubleshooting