Sending a private teams message within C#

Is it be possible to sent private team message within c# with using visual studio 2013. I'm currently building the custom application with following the steps of sent message in a chat https://learn.microsoft.com/en-us/graph/api/chat-post-messages?view=graph-rest-1.0&tabs=csharp. Now I'm facing issue in create an auth provider by reffering https://learn.microsoft.com/en-us/graph/sdks/choose-authentication-providers?tabs=CS .Mostly all Microsoft graph authentication provider needs add the Azure.Identity package. Azure.Identity requires .NETStandard 2.0 which was not supporting by visual studio 2013 any solution to create an auth provider without using Azure Identity Package