Hi @poojamitra88,

I hope you are well today and thank you for your question.

To achieve this, you have to develop custom code in the child theme of Gillion theme as described in the below pages.

https://stackoverflow.com/questions/15629413/how-to-display-the-featured-image-of-a-page-in-the-page-itself-automatically-in

https://wordpress.stackexchange.com/questions/207895/how-to-display-a-pages-featured-image

Developing custom code for custom functionality is beyond the scope of support that we provide here.

If you are not a developer then you can consider hiring a developer to develop it for you. You can hire a developer from any freelance site. Shufflehound recommends the developer https://www.upwork.com/freelancers/~011652ffec8865c6d5

Best regards,
Shufflehound team