I want to enter multiple X,Y coordinate in text boxes and display on the map as graphic in ArcGIS Web AppBuilder widget.
I
I am not sure if this will; give you exactly what you need. You can just use the search bar to search for an XY instead of an address. When it shows the location on the map you can click it and add a marker to the map. It does not add to an operational layer of the map so if you need to do more with that point you might be out of luck with this method.