After installing and activating the Pro version of the theme, install and activate the recommended plugins required by the theme.

Now, you should be able to see the Rara Demo Import via the Appearance Tab. Click on Rara Demo Import and go to Pro Theme Demo Import and click on the Import Now button.

Further you can refer to the blog for importing the demo content via the link – https://rarathemes.com/blog/import-demo-content-rara-themes/