How to build third-party Geany plugins?

After downloading and extracting Geany's JSON Prettifier , and installing yajl, the make command does raise this error: /bin/sh: 1: pkg-config: not found ./geany_json_prettifier.c:32:25: fatal error: geanyplugin.h: No such file or directory compilation terminated. Makefile:16: recipe for target 'build' failed make: *** [build] Error 1 What is left in the system's configuration or Makefile to make it work? Update: under Lubuntu 16.04.