1. What is alternate to Smartforms

You can create your own custom interface intergrating with the K2 api as an alternative.

2. Is there any other integration to store documents other than Sharepoint?

There is a new drop box broker that intergrates with K2 for documents.

3. WHat is the  alternate options on 2FA (multi factor Authentication) ?

There are several different methods for setting up multi-factor authentication. As such, how to set this up depends on what type of authentications you want to use. Additionally, this is something that has to be set up from the server side, rather than the K2 side. Therefore, we do not have any documentation available. If you would like help setting up multi-factor authentication, I would suggest engaging with our Remote Services team, as they would be able to walk you through the setup of the authentication.