ios – substitute session request with session add utilizing Alamofire in Swift?

I’ve a easy perform like this:

func carry out(
    request: NetworkRequest,
    methodology: HTTPMethod,
    parameters: [String: Any]?,
    headers: [String: String],
    success: @escaping SuccessHandler,
    failure: @escaping FailureHandler
) { 

    // present NON WORKING resolution ❌

    let knowledge = JSONSerialization.knowledge(withJSONObject: parameters ?? [:])
    let sessionRequest = session.add(
        knowledge,
        to: url(for: request),
        methodology: methodology,
        headers: HTTPHeaders(headers)
    )

    // earlier WORKING resolution ✅

    let sessionRequest = session.request(
        url(for: request),
        methodology: methodology,
        parameters: parameters,
        encoding: JSONEncoding.default,
        headers: HTTPHeaders(headers)
    )

    sessionRequest.responseJSON { response in 
        // do sth with response
    }
}

I would like to exchange request with add to have chance to trace progress of add. However my CURRENT resolution doesnt work and ends with 401. Why?