CITRIX Viewer: Open with trackpad gesture?

Hello!

I am using CITRIX Workspace. When I start my virtuell Desktop, then CITRIX Viewer opens.

How can I tell Bettertouchtool to open CITRIX Viewer? BT does not find this app?!

Kind regards

Christoph

Edit: CITRIX Viewer is a running app.

How can I tell BT to switch to this running app?