Whatsapps OTP verification implemented in .net core API

WhatsApp's OTP verification in a .NET Core API, you'll need to use the Twilio API for WhatsApp, as WhatsApp does not provide a direct API for OTP verification. Twilio provides a way to send messages to WhatsApp numbers, which can be used for OTP verification.

• Set up a Twilio account: Sign up for a Twilio account if you don't have one already.
• Obtain Twilio API credentials: Get your Account SID and Auth Token from the Twilio console.
• Install Twilio NuGet package: Install the Twilio NuGet package in your .NET Core API project.

dotnet add package Twilio

• Send OTP via WhatsApp using Twilio:

using System;
using Twilio;
using Twilio.Rest.Api.V2010.Account;
using Twilio.Types;

public class OtpService
{
    public void SendOtpViaWhatsApp(string toPhoneNumber, string otp)
    {
        // Twilio credentials
        string accountSid = "your_account_sid";
        string authToken = "your_auth_token";

        // Initialize Twilio client
        TwilioClient.Init(accountSid, authToken);

        // Message body
        string messageBody = $"Your OTP for verification is: {otp}";

        // Send message via WhatsApp
        MessageResource.Create(
            from: new PhoneNumber("whatsapp:"),
            to: new PhoneNumber($"whatsapp:{toPhoneNumber}"),
            body: messageBody
        );
    }
}

• Call the SendOtpViaWhatsApp method with the recipient's phone number and the OTP to send the OTP message.

string recipientPhoneNumber = "recipient_phone_number";
string otp = "123456"; // Replace with your OTP
var otpService = new OtpService();
otpService.SendOtpViaWhatsApp(recipientPhoneNumber, otp);

• Ensure you have configured your Twilio WhatsApp sandbox:
• Set up your sandbox by sending "join " to the WhatsApp number provided in your sandbox settings.
• Configure the incoming message webhook for your sandbox in the Twilio console to point to your API endpoint.