$ sudo apt-get update
$ sudo apt-get install libfxscintilla19 

libfxscintilla19 is installed in your system.

Make ensure the libfxscintilla19 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libfxscintilla19 *

You will get with libfxscintilla19 package name, version, architecture and description in a table

libfxscintilla19 package basic information: