Unfortunately, at this time, OneDrive's API does not offer a default Username/Password feature for the Apps. to take advantage of. The login credentials have to be entered at run-time at the device.
There are feature requests entered for the Apps. that we will be implemented as quickly as possible once OneDrive's API can support default login credentials.
Is there a way to have the Onedrive app remember the sign on info? Especially if its a shared account, I can see how having to sign in everytime to want to scan to or from the folder to be a bit annoying.