makecall.cs

public class MakeCallTest
{
    private readonly ILogger _logger;
    private readonly IConfiguration _configuration;

    public MakeCallTest(ILoggerFactory loggerFactory, IConfiguration configuration)
    {
        _logger = loggerFactory.CreateLogger<MakeCallTest>();
        _configuration = configuration;
    }

    [Function("MakeCallTest")]
    public async Task<HttpResponseData> MakeCall(
        [HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "make/call")] HttpRequestData request)
    {
        var callAutomationClient = new CallAutomationClient(_configuration["AcsConnectionString"]);
        var callInvite = new CallInvite(
            new PhoneNumberIdentifier(_configuration["DestinationPhoneNumber"]),
            new PhoneNumberIdentifier(_configuration["SourcePhoneNumber"])
        );

        var createCallOptions = new CreateCallOptions(callInvite, new Uri($"{_configuration["CallbackBaseUrl"]}/api/handle/event"))
        {
            CallIntelligenceOptions = new CallIntelligenceOptions
            {
                CognitiveServicesEndpoint = new Uri(_configuration["CognitiveServicesEndpoint"])
            }
        };

        await callAutomationClient.CreateCallAsync(createCallOptions);
        
        return request.CreateResponse(HttpStatusCode.OK);
    }
}