How do I put the Bootstrap Collapse plugin in my webpage?

1

I am doing the second challenge under Basic Front End Development Projects. I need to create a collapsible navbar. I read that I need the collapse plugin for that. Where do I get the plugin and how do I put it in my code?

2

Are you using Bootstrap 4.0? read the documentation here. http://getbootstrap.com/docs/4.0/components/navbar/