You can delete all your data at any time by deleting the app and specifying to delete all the data also.
Your data is protected with a login password that is hashed using a quantum computer proof algorithm and stored in the local database.
You will be prompted to setup a password when the application starts up. This is to protect your privacy and the privacy of individuals mentioned in your notes
For convenience you can enable biometrics with your thumbprint or face scan to bypass the password prompt.