How I get error during react app deployment on github pages?

I am following tutorials of how to deploy react application on github pages. I've installed gh-pages using npm, modified package.json adding homepage and scripts to deploy and predeploy. After running "npm run deploy" I get the following error:

events.js:292
  throw er; // Unhandled 'error' event
  ^

Error: spawn git ENOENT
at Process.ChildProcess._handle.onexit (internal/child_process.js:268:19)
at onErrorNT (internal/child_process.js:468:16)
at processTicksAndRejections (internal/process/task_queues.js:84:21)
Emitted 'error' event on ChildProcess instance at:
at Process.ChildProcess._handle.onexit (internal/child_process.js:274:12)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
  errno: -4058,
  code: 'ENOENT',
  syscall: 'spawn git',
  path: 'git',
  spawnargs: [ 'config', 'user.name' ]
}
npm ERR! code ELIFECYCLE
Compiled successfully!

I need your help. I could not find any solutions since hours...