How to Discover Xtreamio on Splunk and what type of credentials need to be used

User is created from GUI and its tested for login it works. Same user when we use to login using splunk, getting access denied in CLI and also below error in Splunk GUI.

"Encountered the following error while trying to update: Error while posting to url=/servicesNS/nobody/TA-EMC-XtremIO/xtremiocustom/xtremioendpoint/setupentity"

When i use Xmsadmin and tech from splunk CLI am able to access XMS host. Not sure how to configure credentials in order to discover xtremio on splunk. Please let me know how to proceed.