So this is the newer model... that I see what you're saying.. no two prongs.
https://www.amazon.com/SHNITPWR-Universal-Adjustable-100V-240V-Converter/dp/B08BL5Y9ZM/ref=sr_1_6?keywords=universal+power+adapter&qid=1680277466&sprefix=universal+power%2Caps%2C89&sr=8-6
So yeah, this one might have issues...

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but the one I've been using forever with success is this...but I have a little bit higher end model.. I remember it costing me around 30$ and it has a sliding switch on the front of the wart to choose voltage.
https://www.amazon.com/ZOZO-Regulated-Switching-Replacement-Electronics/dp/B015PXUHYA/ref=sr_1_23?keywords=universal+power+adapter&qid=1680277466&sprefix=universal+power%2Caps%2C89&sr=8-23

Also, side note, you might want to get some 'Electric Switch Cleaner' from your local auto parts/electronics store. You can spray that in the port and clean it with a q-tip. Sometimes the corrosion on the leads can stop it from working as well. (Works on nintendo carts too) (or just use 99% rubbing alcohol)

Also, I've had to set the voltage one notch up from what it says to sometimes..be careful tho, you don't want to fry anything... so I use that as a last resort.