$AGENT_HOME/bin/emctl listplugins agent -type all

[oracle@srv102-pivot ~]$ emctl config oms -list_repos_details
Oracle Enterprise Manager Cloud Control 13c Release 5
Copyright (c) 1996, 2021 Oracle Corporation.  All rights reserved.
Repository Connect Descriptor : (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=host_oem.speig.fr)(PORT=1521)))(LOAD_BALANCE=ON)(CONNECT_DATA=(SERVICE_NAME=oeme4)))
Repository User : sysman


[oracle@srv102-pivot ~]$ emctl stop oms
Oracle Enterprise Manager Cloud Control 13c Release 5
Copyright (c) 1996, 2021 Oracle Corporation.  All rights reserved.
Stopping Oracle Management Server...
Oracle Management Server Successfully Stopped
Oracle Management Server is Down
JVMD Engine is Down

[oracle@srv102-pivot ~]$ emctl config oms -store_repos_details -repos_conndesc '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=host_oem.speig.fr)(PORT=1521)))(LOAD_BALANCE=ON)(CONNECT_DATA=(SERVICE_NAME=oeme4)))' -repos_user sysman
Oracle Enterprise Manager Cloud Control 13c Release 5
Copyright (c) 1996, 2021 Oracle Corporation.  All rights reserved.
Enter Repository User's Password :
Successfully updated datasources and stored repository details in Credential Store.
If there are multiple OMSs in this environment, run this store_repos_details command on all of them.
And finally, restart all the OMSs using 'emctl stop oms -all' and 'emctl start oms'.

[oracle@srv102-pivot ~]$ emctl start oms
Oracle Enterprise Manager Cloud Control 13c Release 5
Copyright (c) 1996, 2021 Oracle Corporation.  All rights reserved.
Starting Oracle Management Server...
WebTier Successfully Started
Oracle Management Server Successfully Started
Oracle Management Server is Up
JVMD Engine is Up