Do not show featured image

I am redesigning my website and I am using Perth theme. I want to make following changes but I do not know how to make these changes.

In portfolio single item page. Featured image is shown. I do not want this feature image to appear inside the single item page. Kindly visit this link:

Kindly let me know how to make these changes.
Thank you.

Hello there,

To hide it, add this code into Appearance > Customize > Additional CSS in your site dashboard.

.single-projects .entry-thumb {
   display: none;


Thank you, for solving this problem. Love your themes and support.

You’re most welcome here!

Thank you for choosing Perth.