Hi and welcome to the forum
It is not Ichthyophthirius (aka whitespot or ich). Ich shows up as tiny white dots on the fish's body of fins.
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What sort of tank and filter do you have?
Do you have a heater in the tank, if no what is the tank water temperature?
Did you set the tank up yesterday and add the fish on the same day?
If yes the fish is probably struggling with the water and might have been poisoned by the chlorine in the tap water.
Did you use a dechlorinator to remove chlorine/ chloramine when you set up the tank?
If you can post a photo of the fish or s short 20second video clip of it swimming into the corner we might be able to offer more information. A photo of the tank and filter might provide additional info too.
If the filter is too powerful there might be too much current for the fish.
