Unable to find heartbeat. Unable to upload

[oracle@g..1 bin]$ ./emctl status agent
Oracle Enterprise Manager Cloud Control 13c Release 4
Copyright (c) 1996, 2020 Oracle Corporation. All rights reserved.

{some info removed by ADMIN]

Agent Version : 13.4.0.0.0
OMS Version : (unknown)
Protocol Version : 12.1.0.1.0
Agent Home :
Agent Log Directory :
Agent Binaries :
Core JAR Location :
Agent Process ID : 59356
Parent Process ID : 59207
Agent URL :
Local Agent URL in NAT :
Repository URL :
Started at : 2024-09-23 08:24:50
Started by user : oracle
Operating System : Linux version 5.4.17-2136.326.6.el8uek.x86_64 (amd64)
Number of Targets : 7
Last Reload : (none)
Last successful upload : (none)
Last attempted upload : (none)
Total Megabytes of XML files uploaded so far : 0
Number of XML files pending upload : 101