New tab created is not shown in the lms

I have wanted a new tab similar the discussions tab. For that I created Open edX plugin and followed the structure of the discussion application (lms.djangoapps.discussion) and gave it an entry point to the course_tab.

Even though I installed it, I am not able to see that tab in the lms. Is there anything I could check to verify the tab to be installed correctly?

One other thing that would be better if I get to know is how do I add additional _section to lms.djangoapps.instructor.views.instructor_dashboard so that instead of adding a new tab, I could show the required page in that space.

Thanks in advance!