Lots of (mostly) good ideas already in this thread. Throwing out options I haven’t seen mentioned
Some additional places to post are next door and offer up.
You could try taking him flea market that allows animal sales (ours here does)
I’ve seen people mention getting their roosters certified as therapy animals so they can keep them regardless of an ordinance.
You could try and get the ordinance changed.
You could keep him as a house chicken. (Not as crazy as it sounds I swear

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You could talk to your neighbors and see if they would mind you having him... In my opion roosters aren’t really louder than dogs and maybe your neighbors don’t care. If they don’t mind then possibly no one would report you Especially if you have him sleep in a crate inside or in a garage.
At any rate you could print out a letter explaining you got an accidental rooster and that your trying to find a home for him and pass it out to your neighbors. This could encourage them to ignore any temporary crowing and maybe among them there is someone who knows someone who’d want him.
Good luck finding a solution your comfortable with.