The navigation bar is not working on the mobile version

My navigation bar is not opening when I use a smaller screen size. My code is in GitHub https://github.com/valimikayilov/Landing_page . I apreciate any kind of advice.

Thanks!

Don’t you have a live version of the page?

I pasted it to https://codepen.io/Geek-Killer/pen/gVbxOE . There is actually a video on the background but I cannot upload it to codepen.

It apears that I made a mistake on loading the bootstrap, last lines. I am sorry for that.