To recover password, you should have opted for the "Enable password recovery" option in SecNotes app. This is how it works-

You can choose to answer any 3 questions. Your password is encrypted using your answers and is stored in SecNotes cloud backup. Only the encrypted password is stored and not your answers.
You can choose to recover your password by logging into secnotes.com from a browser. The same questions will be shown to you again. We try to decrypt the encrypted password with your answers. Only if all the answers are right, the decryption will succeed and you can see the password. The decryption happens fully inside your browser using javascript and hence is 100%% completely secure. Neither password nor your answers leave the browser any time.

• Login to secnotes.com using the same gmail id as you used in your phone.
• Click the avatar icon and select "Profile & account".
• Click the "Recover notes password" button, answer questions and submit.