Yes, I was able to resolve this problem.
First you need to log into bandlab website using your google account. Then you go to settings --> account and you will see "Change Password". If my memory is right, you don't need to type anything on the "Current Password" section if it's your first time doing this. After you change your password, then you use your Username and the new password to login to bandlab through BandLab Assistant app you downloaded.
This worked for me, and I hope this will work for you too.