Chrome extension not working

[ajayrfhp]

How to get the chrome extension working.
I tried

var dictionary = new Typo("en_US", false, false, { dictionaryPath: "typo/dictionaries" })

 var dictionary = new Typo("en_US");

with typo.js included and dictionaries at the given path.

Both times, script breaks with the console output,

typo.js:255 GET chrome-extension://invalid/ net::ERR_FAILED
Uncaught DOMException: Failed to execute 'send' on 'XMLHttpRequest': Failed to load