How to add console to html

How to add console in Html? because I’m writing Java code but it’s not doing anything because there’s no console.

If you click this button it will open a console


You should see the Crystal Clean repl I’ve made. Take the HTML out the repl and you’ll have a console. I have already done the Python so just copy and paste it where you see the HTML I’ve used

PS, only your account is permitted to use it without credit

I’m assuming you actually mean JavaScript, because this is very, very different from Java and getting those two mixed up is a little confusing.