Or I need to buy something more expensive (e.g. vSphere Standard) in order to use it?
You need vSphere Standard NOT Essentials Plus.
Oh, too poor...
Hey,
vRealize comes fully licensed with vCenter Server standard.
When you have the Essentials bundle you can run the vRealize Orchestrator only in "player mode". This means you can not edit existing workflows or create your own, but you can run the default workflows.