How to add/change toolbar tinymce in wordpress?

Question

TinyMCE

I dug through the documentation, I can’t find anything anywhere ...

I read that this is done something like this:

tinymce.init({
  selector: 'textarea',
  setup: function (editor) {
    editor.on('click', function () {
      console.log('Editor was clicked');
    });
  }
});

And already options are added to init... But the problem is that I can't "connect" to an already existing wordpress editor with this init. New to create - yes. And I need to add a couple of buttons in the floating quickbars to the main one. On top of the "advanced editor tools" plugin.

How to contact him, does anyone know? Or am I not digging there at all? Thanks in advance ;)
If possible, link to "read".