Help needed to attach flue liner to flue collar on wood insert
We are in the process of installing a Hearthstone wood fireplace insert.
What is the best method to use to attach the flue liner to the insert's flue collar?
There are three screw holes around the collar opening. The flue liner is EverGuard Forever Flex.
The documentation for the liner says "the universal connector may be connected to the exhaust collar of an appliance following the manufacturer's fastening specifications."
However, there is no "universal connector" included with the liner.
The Hearthstone manual says to "attach the flue liner to the collar" but doesn't say how that should be accomplished.
Any help with how best to attach the liner to the collar will be very much appreciated.
I can email pictures (not sure if I can post pictures here) if that would be helpful.
THANK YOU IN ADVANCE.