title: Google sheet cannot see my app script
body: <p>I've created my own google app script with one function. However, when I type "=" in sheet cell I can't see this function in suggestions. Also I don't see "Loading..." label which indicates external functions loading. Moreover, I cannot reach this function by name directly. 
  What do I miss in using google app script function with google sheets? Is it bug or should I make some additional configurations?</p>
  
  <p>Thanks for your help.</p>