Google sheet with a button to call apps script which will send an email incognito mode

[Claire Finn]

Hi everyone

Hope you can help. I have a google sheet - bit like an order sheet with lots of products. The sheet and script is deployed with the settings as :

Execute the App as Me

Who has access to the app: Anyone, even anonymous.

Any of the scripts can be run by a trigger - so I know there is no issue with the code in the scripts.

The sheet has a button to send a copy of the spreadsheet as a pdf to a designated email address. This works fine, if I'm logged into my account, or I run the script as a trigger as incognito mode - but not when it's attached to the button. 

When I go to the form url, incognito mode so no one is logged into google and click the button again - I have a doGet error.

Any help would be greatly appreciated as this is driving me insane !

I can post the code if it helps.

Thanks in advance.