This depends on the version of ITAM, and also what type of "integration" you are looking for.
IN ITAM 12.8/12.9, there are some manual steps that need to be done to import the default processes APM uses, and configure a few things with them. Once that is done, ITAM is able to call those processes when an EVENT occurs.
IN the 14.1 release, the import of those processes is done during the installation itself. Still, I go in and check the settings afterwards to make sure.
You can also create custom processes in PAM that APM can call, other than the default ones.
And lastly, APM has Web Services API, which could be called by a PAM process.
So, what are you trying to accomplish with the integration, then we can point you in the right direction.
Rick