Chop the bananas well. Slices are not small enough. Possibly use a chopper or even the hand blender.
Then spread the puff pastry out on a baking sheet lined with baking paper. The parchment paper at the bottom can still be left on. Spread a thin layer of Nutella on the dough and spread the bananas on top.
Roll up the puff pastry tightly using the parchment paper. Make sure that you spread the seam a little more with the roll so that the strudel does not fall apart during baking. Bake with the seam facing down for 15-20 minutes, until the dough is golden brown.
You can certainly use honey or jam instead of Nutella. But please make sure that less is more