If you want to access the microphone and webcam on the user's laptop or phone then the getUserMedia method from the MediaStream API is what you need.
This video talks about how to access the camera and microphone as well as how you can record and save the data that you capture.

An alternative not covered here is saving screenshots from video onto an HTML Canvas element and then saving that in an image element or form input element.

Code GIST: https://gist.github.com/prof3ssorSt3v3/48621be79794a8a3adeed7971786d4d8

Promises Playlist: https://www.youtube.com/watch?v=SmPouEFKOBg&list=PLyuRouwmQCjngZXVn48vYmPK_1yAF-fLw