Hello. I need to change the shape of the courses post on the home page. Please check how it looks like, just like on the demo home page, the courses image shape is square, but I want to know where I can change it to be round.
Please take a look at the link in the private content.

I need this urgently, please help me as soon as possible. Alternatively you can also log into the site and change it but I would like to know how to change it as well. Thank you very much.