ReferenceError: gulp is not defined

Question

I planded backup/mirror all files inside my linux home directory.

my first, the default gulfile task will run and do nothing without errors:

i read here:

• Skip local installation of Gulp

i installed all in and from my home dir:

sudo apt install npm
sudo npm install --global gulp-cli
npm link gulp
npm init
$ gulp
[07:32:43] Using gulpfile ~/gulpfile.js
[07:32:43] Starting 'default'...
[07:32:43] Finished 'default' after 1.24 ms

i read here:

• simple-gulp-copy-file-task

so i produced my first prototype gulpfile.js :

function defaultTask(cb) {
    // place code for your default task here
    // cb();
    gulp.src('./gulpfile.js')
    .pipe(gulp.dest('/media/me/sdd2 ntfs/backup/home/'));

        // .pipe(gulp.dest('./public/'));
  }
  
  exports.default = defaultTask

now i get an error from my first prototype:

ReferenceError: gulp is not defined

$ gulp
[07:49:05] Using gulpfile ~/gulpfile.js
[07:49:05] Starting 'default'...
[07:49:05] 'default' errored after 1.41 ms
[07:49:05] ReferenceError: gulp is not defined
    at defaultTask (/home/me/gulpfile.js:4:5)
    at taskWrapper (/usr/local/lib/node_modules/gulp/node_modules/undertaker/lib/set-task.js:13:15)
    at bound (domain.js:402:14)
    at runBound (domain.js:415:12)
    at asyncRunner (/usr/local/lib/node_modules/gulp/node_modules/async-done/index.js:55:18)
    at process._tickCallback (internal/process/next_tick.js:61:11)

What can i do?