Email Authenticator for MFA not sending an email using the embedded SDK

Questions OAuth/OIDC
1

I’m building authentication into my Next.js (v15) app using the Okta embedded SDK, using the IDX API. I’m struggling with getting the SDK to fire the email challenge when the Okta Email Authenticator factor is chosen as part of my MFA flow. My original thought was that this was a configuration issue with my Okta org or app, but I tested the login in the same Next.js app using the embedded widget instead (pointing to the same Okta app), the email challenge was sent when that authenticator is chosen.

My flow starts with a form with a username and password that hits a server action on submit. Within the server action, I’m starting the idx flow with the authenticate method and passing the username and password.

export const oktaAuthClient = new OktaAuth({
  issuer: `${process.env.NEXT_PUBLIC_OKTA_ISSUER}/oauth2/default`,
  clientId: process.env.NEXT_PUBLIC_OKTA_CLIENT_ID,
  redirectUri: process.env.NEXT_PUBLIC_OKTA_REDIRECT_URI,
  scopes: ["openid", "profile"],
  pkce: true,
  storageManager: {
    token: {
      storageProvider: storageProvider,
    },
  },
  services: {
    autoRenew: false,
    autoRemove: false,
  },
});

function onSubmit(formData) {
  const username = formData.get("username");
  const password = formData.get("password");

  const transaction = await oktaAuthClient.idx.authenticate({
    username,
    password,
  });
}

Upon successful authentication, the PENDING state gets returned with the next step of select-authenticator-authenticate, at which point the app will show the authenticator options; one of which is the okta_email option:

Screenshot 2025-05-08 at 3.44.34 PM
Screenshot 2025-05-08 at 3.44.34 PM1296×540 7.52 KB

When selecting this option, the form handles it with the following SDK function:

function onSubmit(formData) {
  const authenticator = formData.get("authenticator");
  const transaction = await oktaAuthClient.idx.proceed({ authenticator });
}

Which results in the following value for transaction.nextStep:

  nextStep: {
    name: 'authenticator-verification-data',
    inputs: [ [Object] ],
    type: 'email',
    authenticator: {
      profile: [Object],
      resend: [Object],
      type: 'email',
      key: 'okta_email',
      id: <REDACTED>,
      displayName: 'Email',
      methods: [Array],
      enrollmentId: undefined
    },
    canResend: true
  },

My UI then displays the input for the email verification code. I’d expect the SDK to fire the email with the verification code at this point, but it doesn’t. Something that also confuses me is that based on the “Sign in with password and email factors” guide, I should expect the nextStep.name to be “challenge-authenticator”, but it’s “authenticator-verification-data”. I’m unable to find much documentation around this step name.

Is there anything I’m missing that I need to do to initiate an email challenge via the SDK?