Ranks list V1 API call throwing error

Hi,

I am trying to call the following API to get the list of ranks in the community

/restapi/vc/ranks/list

But API call is throwing following error

<response status="error">
<error code="306">
<message>
A required feature is not configured: user-node-rank.
</message>
</error>
</response>

I am confused, what is the feature that I need to configure.

Thanks,  

Srujana Satya Datla.