Not able to answer the questions(TECH. ISSUE)

when working on macOS platform I am not able to write answers, but in windows I am able to. so does this website not work on macOS or is it some technical issue

Are you talking about https://online.codingblocks.com ??
Please explain the exact issue you are facing on macOS ??

it is not letting me write any code in challenges part of the online course in macOS

Our Technical team is looking into it. We will make sure your issue gets resolved as soon as possible.