Where to configure the OnSessionStart event

I want to take some action whenever a new session is started.

I am looking for the OnSessionStart event but I cannot find this inside Service Studio. Whereabouts should I look?

Note - I am using a web application, and I do have a separate extension module which imports my tables from an external database.

try in actions, right click, -> system actions... 


Thanks! I knew it must be somewhere.

Switch to LOGIC tab.
Right-Click on "Server Actions".
Then "Add System Event"