builder.Services.AddFmgLibHttpClient();// ORbuilder.Services.AddFmgLibHttpClient(()=>{JsonSerializerOptionsoptions=newJsonSerializerOptions();options.PropertyNameCaseInsensitive=true;returnoptions;});

Useruser=awaitHttpClientHelper.SendAsync<User>("REUQEST_URL",HttpMethod.Post,jsonRequestContent,ClientContentType.Json);