You can look for the change password function on the Preferences setting of APP. If the change password function is not available, you can try to reinstall GFE APP again. During the re-installation, I guess you can set your password.

When you setup the GFE APP, it will ask you input the PIN. You can input the original PIN on email. But if your administrator set the PIN is only valid for one time and the original PIN is invalid, you have to ask the administrator to create your account again.