ML is not available

Recently I started to work with ELK 6.3. I know that ML is enabled by default in both Elastic and Kibana, But when I get _xpack API, It says that ml is not available, And there is no machine learning tab in Kibana menu.
I installed both Elastic and Kibana on a 64 bit Ubuntu 14.04 VM.

What else should I do to use ML?

It seems that ML is not available in basic license :disappointed_relieved:

Hi Vahid, if you'd still like to try out ML you can do so with a 30-day trial license.