Unfortunately Fitbit and Garmin do not always allow us to recognize you again after (re)installing an app, so our system might think you are a new customer when that happens, and might ask you to pay again.
Luckily you can unlock your app again for free here.
Just enter the code it is showing you and the e-mail address you used for the original purchase and you will be up and running again in no time.
Updated on: June 24th, 2020