IMHumbO you'll be lucky to rehome it for free. Channel catfish grow to 2.5'-3' in captivity and are way too big for 99.999% of fish tanks people own, they eat a ton, they are not lookers, they are not popular with peers mostly kin on keeping exotics, they are a dime a dozen when/if they are available, they can be caught by almost anyone in the USA if they wanted them for their pond, etc.
Nevertheless, I don't wanna be a complete downer and wish someone will help you out soon.