OTP Time Out

To implement an OTP (One-Time Password) generation functionality with a 30-second timeout, you can follow these steps:

Approach

1. Generate the OTP and store it with an expiration time (e.g., 30 seconds from the generation time).
2. Display the OTP and start a countdown timer for 30 seconds on the UI.
3. Invalidate the OTP after 30 seconds, either in the backend or on the client side.

Hi 
Have you called the below function in your code?

// Call startTimer() after generating the OTP

startTimer()

If not, call the function above and check again.  
If the issue still exists, share the code you tried, and I’ll assist you.

but here not decrese the time why

OTP session timeout Example

Front end 

Generate OTP
Your OTP: 
Time remaining: 30 seconds

.NET (Backend):

[ApiController]
    [Route("api/[controller]")]
    public class OtpController : ControllerBase
    {
        [HttpGet("generate")]
        public IActionResult GenerateOtp()
        {
            Random random = new Random();
            int otp = random.Next(100000, 999999); // Generates a 6-digit OTP
            
            return Ok(new { Otp = otp });
        }
    }

To implement an OTP session timeout in a .NET application, you can utilize a combination of a timer and a simple user interface update.

public class OtpService
{
    private static string _otp;
    private static DateTime _otpGeneratedTime;

    public string GenerateOtp()
    {
        _otp = new Random().Next(100000, 999999).ToString(); // Generate a 6-digit OTP
        _otpGeneratedTime = DateTime.Now;
        return _otp;
    }

    public bool IsOtpValid()
    {
        return (DateTime.Now - _otpGeneratedTime).TotalSeconds < 30; // Check if OTP is still valid
    }
}

In your front-end, you can use JavaScript to handle the countdown timer:

let countdown = 30;
const otpDisplay = document.getElementById('otpDisplay');

function startTimer() {
    const timer = setInterval(() => {
        if (countdown <= 0) {
            clearInterval(timer);
            otpDisplay.innerText = "OTP expired";
        } else {
            otpDisplay.innerText = `OTP valid for ${countdown--} seconds`;
        }
    }, 1000);
}

// Call startTimer() after generating the OTP

This implementation generates an OTP and starts a countdown timer, displaying the remaining time until expiration. After 30 seconds, the OTP is considered invalid.