I'm using Google Drive&SpreadSheet API to output my work. The successful example results should be like this: Example
However, my output won't ever show the image. Opening the image link giving me a 403 page.
I've researched Google handle error but 403 includes multiple situations. I have no idea what situation my 403 could be. I've also checked some past question. But mine doesn't even have an error message returned(only with a 403 page). Could anyone lesson me a clue about this problem?