Closing pool with Cyclone - skimmer hole has no threading

[dpado]

I have a fiberglass pool with one skimmer. I am closing my own pool for the first time and have purchased a Cyclone Pro air blower to blow out the lines. The Cyclone comes with a hose adapter to screw the hose into the skimmer.

First question: The skimmer has the two holes. One is the same that I hook my hand-held pool vac to (because my stupid Dolphin vac broke this year). It is the same hole sucks the small debris down - which leads to the filter. The other one is the equalizer - I believe. (it doesn't have an OPEN hole). I'm 99% sure that the hole I need to screw the hose adapter into is the same one I hook my hand-held pool vac to.

Second question: Assuming I'm correct in my assumption above - I need to screw the hose adapter into the first hole that I described. Problem is - this hole does not have any threading. (The equalizer hole does have threading). How do I get a good seal with the blower if the correct hole has no threading?

Thanks!