After Single Sign-On (SSO) has been enabled on an On-Premise system, how can that be changed back to logging in with the WaspCloud username/password screen?

Run script in SQL Server Management Studio in order to enable logging in with both SSO and Wasp's username/password credentials.

/* begin script */
Update [WaspTrack].[dbo].[app_option]
set app_option_value = 'WaspCloud'
where app_option_code='1000'
/* end script */