Below situation was not documented in the OMI - APM guide so that customer had difficulties with troubleshooting and finding solution.
Steps 2 of OMi - APM failed due to integration user issue although integation user was created in RTSM jmx console. LDAP is used on APM side and no equivalent user was created in APM console.
The issue was only fixed after disabling LDAP in APM and creating the same integration user in APM console with SuperAdmin privilege.
Referring to QCCR8D36933 those steps also mentioned to be done but in the guide still not includes it yet