Only seen a few planes that would ever do it. You need at least 2.5:1 power to weight ratio. Your bipe may have plenty of power but not that kind of power. Most of the planes that will do a climbing flat spin are profiles.
To get into one enter a normal flat spin. (full down , full left aile , full right rudder, idle) Find the sweet spot by moving the ailes toward the center while slowly increasing power. Once you find this spot with the plane in a good flat spin start to increase throttle and reduce the amount of elev. Too much elev and the plane will start to flip and many times go into a knife edge spin. It's a delicate balancing act to find the right spot in the sticks. make sure you have a bunch of ALT.