To test a bot's authentication flow that prompts for credentials, the emulator must be configured to handle the security handshake.

1. Use version 1.0 authentication tokens: This setting enables the authentication feature in the emulator, allowing it to process the security tokens required to communicate with an authenticated bot.
2. Use a sign-in verification code for OAuthCards: This is crucial for the interactive sign-in process. When a bot sends an OAuthCard to initiate login, this setting ensures the emulator will display an input box for the user to enter the verification code they receive after successfully logging in via the browser pop-up. This completes the authentication flow.
3. Use your own user ID to communicate with the bot: This associates the generated authentication token with a specific, consistent user identity. This is necessary for the bot to manage user-specific state and recognize the user as authenticated in the context of the conversation.

Microsoft Corporation. (2023). Debug with the Bot Framework Emulator. Microsoft Docs.

In the "Sign in to your bot" section, the documentation explicitly instructs the user to enable all three of these settings to test authentication: "Enable Use version 1.0 authentication tokens", "Enable Use a sign-in verification code for OAuthCards", and "Enable Use your own user ID to communicate with the bot...".

Microsoft Corporation. (2023). Add authentication to a bot. Microsoft Docs.

Under the section "Test the bot," it describes the authentication process involving a sign-in card and a verification code ("magic code"). It states, "The Bot Framework Emulator... has a specialized UX for the sign-in flow" which is enabled by the settings identified in the correct answer to correctly handle the OAuthCard and token exchange.