I would use this map and information:
https://touringplans.com/hotel_maps/disneys-pop-century-resort
There are no preferred rooms with a fireworks view. You would need to change to a standard room.
Just a heads up that due to the trees, etc, watching fireworks from outside your room will be greatly hampered from many rooms. e.g. this is the view from a 4th floor looking towards fireworks:
View attachment 674887
If you wish to request a room facing the firework you will want to request Building 4: 4437 - 4460. Possibly some rooms in block 3413 - 3436 may have some viewing also.
We normally walk downstairs and watch them from the walkway near the lake.