Need help; trying to create a code snippet in insert mode.

[aGIToz]

I want to create a code snippet.

Here is an elementary challenge I am trying to solve.
Basically I write "arr" in insert mode and it is converted to "superarray".

In vim one can use imap to create some code snippets I am trying to do the same here.
But it is not working how to make it work?

require([
  'nbextensions/vim_binding/vim_binding',
], function() {
  CodeMirror.Vim.map("arr", "mysuperarray", "insert");
});