You must provide a second authentication factor to finish login.

Unauthorized

This indicates that the username or password is not valid or the system denied the requested access.

Forbidden

This indicates that the IP address is banned due to too many login failures or it is not whitelisted (when WHMCS API IP restriction is enabled).

Conflict

This indicates that the same operation is already in progress for this resource.

Precondition Fail

This indicates that Two-Factor Authentication is required or the provided Two-Factor Authentication token is invalid.

Invalid input

Too Many Requests

The request passed a rate-limited endpoint's allowance. For more information, see Rate Limits.