by default the Create Component returns the primary key of the managed element. In your case you can add a Parameter (e.g. oid) to the OK Port of your Action and pass the oid value returned by the Create Component. Moreover this parameter can be propaged over the OK Flow starting from the Action.
Anyway you have to define an Attribute on your Entity marked as Key (it is the primary key).
Please for more details refer to related guides available on WebRatio Learn section. For example: