Error when using chrome.notifications.create "Uncaught TypeError: Cannot read property 'create' of undefined"

There are 2 possible causes.

• You are trying to use this from a content script. You can't: content scripts are very limited in what Chrome APIs they can call.

  However, content scripts have some limitations. They cannot:

  Use chrome.* APIs, with the exception of:
  extension ( getURL , inIncognitoContext , lastError , onRequest , sendRequest )
  i18n
runtime ( connect , getManifest , getURL , id , onConnect , onMessage , sendMessage )
  storage

  In that case, you need to delegate this call to a background script: send a message from the content script, get it in a background script and execute the action.

• You are trying to call it from an extension script, but did not declare the "notifications" permission.

  In that case the fix is trivial - just add the permission.

Have you added the chrome notifications permissions to your manifest.json?

adding permissions: ["notifications",//other permissions here]

The permissions deals with what is and isnt loaded in your extension, and what you have access too.