1

Initialize Turnkey

import { Turnkey } from "@turnkey/sdk-browser";

const turnkey = new Turnkey({
  apiBaseUrl: "https://api.turnkey.com",
  defaultOrganizationId: process.env.TURNKEY_ORGANIZATION_ID,
});
2

Configure the Sub Organization for the User

import { DEFAULT_ETHEREUM_ACCOUNTS } from "@turnkey/sdk-browser;"

const subOrganizationConfig = {
  subOrganizationName: <subOrganizationName>,
  rootUsers: [{
    userName: <userEmail>,
    userEmail: <userEmail>,
    apiKeys: [],
    authenticators: [],
    oauthProviders: []
  }],
  rootQuorumThreshold: 1,
  wallet: {
    walletName: <walletName>,
    accounts: DEFAULT_ETHEREUM_ACCOUNTS
  }
};
3

Call createSubOrganization from your backend

await turnkey.serverSign("createSubOrganization", [subOrganizationConfig]);
This is all that is needed to create a user without any authentication credential other than their email address, in the login flow you can see how to then authenticate the user after their subOrganization is created.