como usar o atob no javascript es6

Decodes a string of data which has been encoded using base-64 encoding.

Create a Buffer for the given string with base-64 encoding and use Buffer.toString('binary') to return the decoded string.

const atob = str => Buffer.from(str, 'base64').toString('binary');

atob('Zm9vYmFy'); // 'foobar'

Acesse a Referência original