The .sif file can be imported from the initial start screen in CAMduct 2016, under "Actions" you will find "Import Statuses"

See screen capture below.

The Help file you are referencing looks like it is still refering to the original "Trackit" program and hasn't been updated to reflect the changes made since it became "Tracker".

Also if you are running Tracker on the same network as your CAMduct program you don't need to import a .sif file, simply configure Tracker to share the same database and it will update the statuses directly.