Follow these steps to fix this problem:
Make sure you have an account with Amazon.
I know, log in your Amazon account.
Manage your kindle- Simply navigate to "Your account" menu and then choose "Manage your kindle".
You can find your account in the upper right next to the search bar.
Manage devices - Go to "manage your devices".
You can track the option on the left side of the sidebar, which will be linked directly to the Amazon account.