If you have forgotten your Secure Folder password, you can reset it by confirming the Samsung Account you used to set it up.
1. Open Secure Folder on your device.
2. Tap FORGOT PASSWORD.
3. On the next screen, login with your Samsung Account. If you forgot your Samsung Account password, reset it here.
4. In the pop up box, tap RESET.
5. You are taken to the lock screen settings, choose a new authentication type, such as PIN or PASSWORD.
6. Enter your new password.