What is my Apple ID?
NotePlan syncs your notes and checks your subscription using the Apple ID linked to your device’s settings. To access the web version (and all your devices), you must use this same Apple ID.
Here is how you know which Apple ID you are using.
iOS
1. Search for the app "Settings" and open it.
2. Tap on your profile at the top of the settings.
3. See your email address below your name.