How to run system command on heroku server?

I am using OGR2OGR for converting geojson file into dxf format. It is working on local server but on heroku server it is not working. Find code which is using for genrating file:

• str2 = {"type":"FeatureCollection", "features":[ {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@substation]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@feeder]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@form3]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@pdt_array]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@edt_array]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@composite_array]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@al_array]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@tp_array]}}, {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"Point","coordinates":[@ot_array]}},

   {"type":"Feature","properties":{"color":"red"},"geometry":{"type":"LineString","coordinates":[@lt_array,@ht_array,@consumer_array]}}
  
  

  ]} path = "#{Rails.root}/public/data.geojson" File.open(path, "w+") do |f| f.write(JSON.pretty_generate(str2)) end system("ogr2ogr -f DXF #{Rails.root}/public/delhiii.dxf #{Rails.root}/public/data.geojson")