are you after the call traces of a single call, for diagnostic purposes or after call records. for call records use CAR not RTMT as @j.huizinga mentioned
Call Logs can be provided by CUCM Unified Serviceability Page->Tool->CDR Analysis and Reporting.
Then, you may select CDR->Search by User/Phone Number/SIP url and specify the specific user and the time period on the call records you need to check.
RTMT tool is mostly used in cases where you need to do troubleshooting, for example for SIP debugging or Services Monitoring.
As others have mentioned, the built in CAR will allow you to view CDR records. If you'd like another option, check out the free tool VoIP Detective. It will allow you to view call records for the previous 7 days.