Toolgal,
You need to get a tap block that fits your Uniclick. You snap the long side in and then using the tap block, tap the new piece down into the piece beside it. The tap block protects the tongue and grooves. Also there are fairly wide plys that are designed for this system they have a small turn down on one end to catch the end of the last piece and a larger turned up flange for you to hammer against.
Good luck,
Jim
'Just a handyman trying to help'