node-gyp configure to release mode

Hi I am trying to compile a node_modules as Release mode, but I could not successfully configure as Release mode.

I ran node-gyp configure; the configure.gypi generated

 # Do not edit. File was generated by node-gyp's "configure" step {
   "target_defaults": {
         "cflags": [],
         **"default_configuration": "Debug",**
         "defines": [],
         "include_dirs": [],
         "libraries": []   },

I tried with -DBUILDTYPE=Release and BUILDTYPE=Release but not successfully