what is the input source for watching Netflx or Amazon on my Visio E-400i B2 smart TV. I can get Netflix but not Amazon.

What you are saying, my car can take me to Walmart, but I can't get to Safeway.

In order to get to a site (you are getting video from an Internet, outside of your home place) the TV needs an APPLET (a piece of software that talk to that particular site). You need a separate applet for EACH site. You probably haven't noticed this because your remote has a NETFLIX button and everything is automatic. Your TV may not have an Amazon applet.

HERE is a list of compatible devices that can get Amazon videos.