How to approve a role creation in OIA?

Hi experts,

I am new with OIA and there are some things that I can not understand from documentation. Mostly regarding to workflows. For example, in Workflow creation I set a single step with Role Owner approval. How global user makes the approve? Because as far I can see only OIA Users have a password to log into console and "my requests" menu. Is some way to link OIA user to global user? Is a way to make an autoapprove when roles are clicked for creation in Identity Warehouse section?

And a finally and more complex question, is where can I get deeper documentation, to learn how the filesystem workflow configuration files works and how are related to UI workflow design.