Yes, you can log in on other devices by using the same login credentials. But if you logged in previously through your Google account or Apple ID and can't log in on other devices now, then you should request a password by clicking the "Forgot password?" button and entering your email associated with your Google or Apple account. Once you have reset your password, you can enter your Google email or Apple ID and your new password to log in on the other devices.
Please note that if you subscribed through Apple, it is possible that the email you used to create your Flightradar24 account and subscribe to our subscription is anonymized with Apple's Private Relay feature (these emails end in @privaterelay.appleid.com or @icloud.com). If that is the case, you should use this anonymized email address to log in on other devices and to reset your password. To check which email is associated with your Flightradar24 account, you should go to our app and tap the user icon in the top right corner of the screen. Your Flightradar24 account email address will be displayed to you in the next window.