Why this code is not working in sololearn

Question

This code is working in my pc but it is not working in sololearn. It shows addeventlistner is not working, please help
https://code.sololearn.com/Wz141DT01akj/?ref=app

Answer 1

Read this post to get a better understanding about this issue.

https://www.sololearn.com/post/90825/?ref=app

And you have a typo writing "cacnum" while there should be "calnum"

btn.addEventListener('click', cacnum);

Answer 2

In your javascript line no - 13 calnum spelling is wrong.

your - btn.addEventListener('click', cacnum);
should be - btn.addEventListener('click', calnum);