Some organizations have implemented multi-factor authentication (MFA) to restrict access to their CRM. MFA is a way to prompt a user to enter a code or use another means to verify their login attempt after entering his/her user credentials.
Currently, Click does not support multi-factor authentication for our service user that connects to your CRM when using Username + Password Authentication. The reason for this is that in order to use multi-factor authentication via the CRM SDK, an application can only use the WebAPI oData endpoint for SDK operations. At this time, the WebAPI does not include some of the operations and methods available in the mature Organization.svc SOAP endpoint.
However, multi-factor authentication can still be used when using either Application User or Single Sign On (SSO) authentication. For more details on these authentication types, please see our Application User article.