$ sudo apt-get update
$ sudo apt-get install qtcreator-plugin-ubuntu 

qtcreator-plugin-ubuntu is installed in your system.

Make ensure the qtcreator-plugin-ubuntu package were installed using the commands given below,

$ sudo dpkg-query -l | grep qtcreator-plugin-ubuntu *

You will get with qtcreator-plugin-ubuntu package name, version, architecture and description in a table

qtcreator-plugin-ubuntu package basic information: