external certificate in Splunk

[jambs001]

We are in the process of implementing SAML configuration in Splunk, utilizing an external .pem certificate. However, Splunk does not accept this certificate. How can we obtain an external certificate in Splunk to successfully configure SAML?
Additionally, for SAML integration, we are utilizing NetIQ Access Manager.

[jswann_splunk]

https://docs.splunk.com/Documentation/Splunk/9.1.2/Security/HowSAMLSSOworks