Extending SuccessFactors Employee central on HCP

I have to extend the  SuccessFactors Employee central on Hana clouf Platforms.

I went to  the path   in Success factors.

Administrative tools -> Company Setting -> Extensions

But I am not getting any place to create an New extension.

This should work as per the attached screen shot.

Please let me know if any one has worked on similar requirement.

Thanks,

Shreedhar Gangadhar