TOTP - Generate QR code and verify users provided code .NET Core

[tranphuongyd]

I'm very new in Ory. Currently I'm using Ory.Kratos.Client and Ory.Hydra.Client to work with Ory Kratos (self-host) and Ory Hydra (self-host) in .net core web api.
My current settings for totp:

methods:
    password:
      enabled: true
    totp:
      config:
        issuer: Kratos
      enabled: true

And the kratos-selfservice-ui already work with the 2FA TOTP. But I get some troubles in the web api when generating url to return to the front-end app to generate QR code and verify.

1. Seems the url look like otpauth://totp/Kratos:{identityId}?algorithm=SHA1&digits=6&issuer={my-issuer}&period=30&secret={base32Secret}. Can we get this url from the Ory Kratos API? Or we need to manually combine those values? If manually, how to generate the base32Secret? My current code is

var secret = KeyGeneration.GenerateRandomKey(20);
var base32Secret = Base32Encoding.ToString(secret);

var sessionToken = await SessionService.GetSessionAsync(identityId);
var settingsFlow = await _frontendApi.CreateNativeSettingsFlowAsync(xSessionToken: sessionToken);

await SessionService.StoreSessionAsync(settingsFlow.Id, sessionToken);

return new QRCodeResponse
{
    FlowId = settingsFlow.Id,
    QRCode = $"otpauth://totp/Kratos:{userId}?algorithm=SHA1&digits=6&issuer={issuer}&period=30&secret={base32Secret}"
};

2. For verifying users provided code (get from user authenticator app), I have used UpdateSettingsFlowAsync with KratosUpdateSettingsFlowWithTotpMethod body. But always get response "The provided authentication code is invalid, please try again."

var sessionToken = await SessionService.GetSessionAsync(flowId);
var settingsFlow = await _frontendApi.CreateNativeSettingsFlowAsync(xSessionToken: sessionToken);
var method = new KratosUpdateSettingsFlowWithTotpMethod(method: TOTP, totpCode: totpCode);
var body = new KratosUpdateSettingsFlowBody(method);
var updatedFlow = await _frontendApi.UpdateSettingsFlowAsync(settingsFlow.Id, body, xSessionToken: sessionToken);

Can some one help me? Because I did not found any guide line documents for it

[aeneasr]

If configured correctly, the TOTP QR code is returned as part of the GetSettingsFlow response in base64 format

[tranphuongyd]

Thanks @aeneasr for your support! I have resolved the issue.