Vincent, You may also use the "Admininstrator sets usernam and password" when setting up and assigining the application in the Okta admin console. This would require an administrator to enter the username and password for each application assiginment, and is not valid for group assigined applications.
Okta requires the user to enter the password for all SWA applications one time only. The best alternative to use a SAML intigration where avaialble from the Service Provider. If Okta does not have the application as a SAML intigration in the Okta Application Network but the Service Provider is offering SAML kindly use the Application Wizard to complete the intigration.