Google Sheets

I DON'T SEE MY THUMBNAIL IMAGE ANY MORE.

If you use the Image field, your thumbnail URL will be expired due to Google's security reasons. 

To handle this issue, make sure your thumbnail URL is a universal link for google drive. 

Go to your Google Drive and change your image permission to Anyone on the internet with this link can view . 

Under the ThumbnailURL column, change the url to this format: https://drive.google.com/thumbnail?authuser=0&sz=w220&id=[fileid] 

For example, if your Image column has; https://drive.google.com/file/d/1fp9BVppa6OEteJCgzATFmoH2YGID39xP/preview 

Paste the following URL under ThumbnailURL: https://drive.google.com/thumbnail?authuser=0&sz=w220&id=1fp9BVppa6OEteJCgzATFmoH2YGID39xP 

Go back to the app and rescan the code and you will see that thumbnail image is displayed properly.