OnSong can integrate with your favorite content providers like CCLI SongSelect. When you first access SongSelect, or if you had signed out of SongSelect, you will be prompted to sign in using your SongSelect credentials. The authentication process is handled completely by SongSelect's services so if you are having trouble accessing your account, receive a bad username/password notice, or have other such issues, it's likely caused by an issue with your SongSelect account or the SongSelect service.
Please consider contacting SongSelect if you are having issue authenticating. You can also access their support pages to answer common problems.
One common issue is that the SongSelect web service requires the date and time of your device to be accurate for validating security credentials. If you are having issues, please check that you have the date and time on your device set to "Set Automatically". To do this, open the Settings app on your iOS device and choose General > Date & Time. Ensure that the "Set Automatically" switch is enabled.