KB: Cannot find option to import KiCAD files

Solution Details

A KiCAD importer was added to Altium Designer with the release of AD20.1: Added New KiCAD Importer

Importing a Design from KiCad

You will need to add the extension from the Purchased tab of the Extensions & Updates page. Here's documentation that will help you with that:
 

 

Once added so the extension is listed now under Installed tab, invoke File » Import Wizard, and KiCad Design Files should appear as one of options.

You can download/install our current (or an older) version from here:  
ALTIUM DOWNLOADS