How to set the project attribute "TranslationKitUser"

When i want to use the Automatic Action "Generate TranslationKit" it is essential to set a human step after the AutoAction to generate the TranslationKit. To get this right the AutoAction "Generate Translation Kit" looks for into the reserver project attribute "TranslationKitUser".

My question now is: How do i set the Attribute "TranslationKitUser"?