You have to make sure that you are attempting to log in to the correct server that your account was created on. You can do this by logging with the linking method you previously used, you can tap on the ">>" next to the server name > Recent Login > See Recent Servers.
You can try all possible linking methods that you might previously use and make sure that you are logging in with the correct Gmail/ Apple ID/Facebook account that you initially used.
If you are unable to find your account in Recent Login, please make sure you are connected to the correct account. Tap the "X", and account on the top left corner of the screen. Try both to see if you are able to locate your account by replicating the above steps.
If you played on a Guest account, unfortunately, we are unable to do anything for you unless you linked your account to your Facebook / Google, Apple, even when you know its UID. Once you uninstall the app or log out of your account, all your data will disappear.