It appears that the repository has undergone several changes and renamings:

backend/node_modules/autoprefixer/bin/autoprefixer

@@ -1,22 +0,0 @@
-#!/usr/bin/env node
-
-let mode = process.argv[2]
-if (mode === '--info') {
-  process.stdout.write(require('../')().info() + '\n')
-} else if (mode === '--version') {
-  process.stdout.write(
-    'autoprefixer ' + require('../package.json').version + '\n'
-  )
-} else {
-  process.stdout.write(
-    'autoprefix\n' +
-      '\n' +
-      'Options:\n' +
-      '  --info    Show target browsers and used prefixes\n' +
-      '  --version Show version number\n' +
-      '  --help    Show help\n' +
-      '\n' +
-      'Usage:\n' +
-      '  autoprefixer --info\n'
-  )
-}