Dear Rohan,
Have you installed the Pro theme properly? You can see the steps below to find the license key.
For entering the license key in the admin panel:
The option for theme license will appear in the Dashboard.
You can click on Appearance, the Theme License section will appear under the name of the theme you are using.
http://prntscr.com/xBvGa75iqPY9
Best Regards!