Setting up a UF in the Linux source server using CLI commands (receiving enabled in Splunk server), how can I get logs in the server?

Hi Team, I've set up the Universal Forwarder(UF) forwarder in the Linux source server using CLI commands and also enabled the receiving in the Splunk server. but I still don't see any logs in the Splunk server. can someone help? The log I'm monitoring is an app log, not any syslog.