I completed the course but I don’t remember well. Can I start over?
I guess you can try deleting your cookies of play.kotlinlang.org. That should work
Ok, this was not a smart question. I solved exercises in Intellij and surprisingly figured out that the answers comes from Stepik account. Just logged out and started a new course project.
On the web page (play.kotlinlang.org) in Chrome, I clicked on the lock (for connection next to URL), selected “Cookies”, under Allowed opened play.kotlinlang.org and selected “Local storage” and clicked on “Remove”.
Refreshing the page now shows “Progress: 0%”
This doesn’t effect other cookies if that is important to you.