Is it a must i create two navbars(one for desktop and the other for mobile)or is it something media queries can do with just one

Question

Html CSS and mediaqueries

Answer 1

https://www.w3schools.com/css/css_rwd_mediaqueries.asp

See this tutorial.

edit: Here is one more with bootstrap.
link: https://www.w3schools.com/bootstrap4/bootstrap_media_objects.asp