The Shimano crank-based meters you identified aren’t compatible. I glanced at the bike model on Amazon. It doesn’t list a specification sheet, but it doesn’t have Shimano cranks. To use the Stages or any similar crank-based power meter, you need a standard crankarm from one of the big 3 drivetrain manufacturers that the manufacturer goes and validates for its power meter. The indoor bike you pointed to does not use off the shelf cycling components as far as I can tell.
All the single-sided pedal power meters are a bit cheaper, so that’s a possible option.