encoder.encode("1") debugDescription : "Top-level String encoded as string JSON fragment."

[Toj-dev]

// debugDescription : "Top-level String encoded as string JSON fragment."

mutating func encoded(encodable: Encodable, encoder: JSONEncoder = JSONEncoder()) throws -> URLRequest {
do {
let encodable = AnyEncodable(encodable)

        // encodable is  primary data type(int / double/ string)
        httpBody = try encoder.encode(encodable)

        let contentTypeHeaderName = "Content-Type"
        if value(forHTTPHeaderField: contentTypeHeaderName) == nil {
            setValue("application/json", forHTTPHeaderField: contentTypeHeaderName)
        }

        return self
    } catch { 
        throw MoyaError.encodableMapping(error)
    }
}

[Toj-dev]

iPhone 5s
iOS12.5.7