Three routes at fixed heights
Read the upper row across the top windows of all columns. Repeat that idea for the centre and lower rows. Each route contains one window from every reel, giving a total of three symbols to inspect.
The moving columns themselves are not scoring lines. Their fixed sequence would make them a different kind of pattern, so the site and written rules both exclude them.
Two corner-to-corner routes
The descending diagonal connects upper left, centre and lower right. The ascending diagonal connects lower left, centre and upper right. A matching pair can occupy the two endpoints even if the centre is different.
The board highlight shows which windows belong to a selection. Check those three names rather than counting a nearby matching symbol that sits outside the route.
One route decides the award
A triple earns four counters and one matching stamp, a pair earns two and one stamp, and all different symbols earn one counter. Only the selected pattern is collected during an ordinary turn.
In a puzzle, the Check move button compares that legal award with the stated target. A result can be legal yet miss the challenge. Resetting the puzzle lets you inspect another candidate from the same starting arrangement.