l298n voltage loss when motor attached
From an L298N datasheet:

TOTAL DC CURRENT UP TO 4 A

From motor's &quot;datasheet&quot;:

I'm no expert in electric motors and driving them, not even sure I'm novice level, but I just don't see you driving a motor anything near this current draw with this part.  If by some miracle you can, it will be horribly inefficient owing to the losses associated with the voltage drops that Gil mentions.
For a motor that operates with this much current I would expect a practical h-bridge setup to have discrete mosfets, perhaps mounted to a heatsink.