Connection error when configuring SSO with OKTA with SAML

HI,

I'm adding a new SAML configuration for Okta and to save it I have to make a successfull verification before.

The problem is we fail to establish the connection so the Test return false. When the user tried it has the error below :

"Authentication was unsucessfull

Reason : the user tested with was invalid"

Nevertheless, the user connected is a valid user of the Appian application (and is system Admin).

Regarding the Tomcat logs, I see this error :

2023-06-22 10:18:13,730 [http-nio-8080-exec-1535] ERROR com.appiancorp.security.auth.saml.SamlTestServlet - Error occurred during SAML authentication test: Invalid Username
com.appiancorp.security.auth.saml.exception.InvalidAppianUserException: Invalid Username
	at com.appiancorp.security.auth.saml.SamlAuthenticator.getAppianUserProfile(SamlAuthenticator.java:100)
	at com.appiancorp.security.auth.saml.SamlAuthenticator.authenticateUser(SamlAuthenticator.java:54)
	at com.appiancorp.security.auth.saml.SamlTestValidator.validate(SamlTestValidator.java:44)

Would you have any idea ?

Regards