I don't think you enter it directly on the 7206 worksheet (and Form 7206 isn't required in most situations, despite what ProSeries does, but that is another story ....)

On the K-1 worksheet, look right above Box 1.  There should be a "Quickzoom" button that says something about health insurance.  That opens up a new worksheet, and you enter the insurance cost and Box 5 of the W-2 there.  That should automatically flow to the 7206 worksheet.