您需要将具体类型传递给JSONEncoder.encode，因此您需要在Encodable(Codable不需要，因为它太严格了.)

You need a concrete type to be passed into JSONEncoder.encode, so you need to make your function generic with a type constraint on Encodable (Codable is not needed, its too restrictive).

func encodeRequestJSON<T:Encodable>(apiRequestObject: T) throws -> Data {
    return try JSONEncoder().encode(apiRequestObject)
}