If your organization has Single Sign-on (SSO) enabled, your login process will slightly differ from the usual one.
Instead of entering your Productive account credentials, you will need to use the Username and Password from your SSO provider (Gsuite, Azure, Okta).
Also, you will need to select the following option from the login screen:
Note that this option is available for employees and contractors of an organization. The clients will need to log in with their login credentials.