If you have forgotten your password to log in to Birda, you can always reset it by following these steps:
Open the app
Tap on 'Sign in' in the bottom right
Tap on 'Forgot password' below the email and password fields
Enter your email address and tap 'Continue'
Open your email client
Look for an email from Birda titled 'Reset your password'
Open the link and reset your password
Open the Birda app and log in using your email and new password
This video shows steps 1 to 4 described above