How to create and consume async/await asp.net web service

Hi,

 I have asp.net asmx web service which was implemented using async await as below,

    public Class SolutionService
        {
        [web method]
        public Async Task<Result> GetSolutions(string s1,int p1)
        {
           //some code here  
            var result = await GetDetailsfromotherService(s1,p1);
            return result;
        }
        }     

 I could see follwoing classes in proxy class generated using wsdl.exe ,
    
      TaskOfResult GetSolutions(string s1,int p1),
        IAsyncResult BeginGetSolutions(string s1,int p1),
        TaskofResult EndGetSolutions(string s1,int p1),
        void GetSolutionsAsync(string s1,int p1),
        GetSolutionsEventHandler GetSolutionsCompleted
        private OnGetSolutionsOperationCompleted
    
Can you please help me how to use these proxy classes to send an async request and reseive the response ?

My requirement is to create a async web service and consume it  asynchronously with async/await.We  are using .Net Framework 4.6 and our web service is legacy service.

Please let me know if you need any further details.

Thanks in advance.