Cannot open file from Google Drive

I get “Bad Request” when I try to open a PDF file from my Google Drive. I’ve checked that the file name and path match.
The file has been generated by the same appsheet app, therefore I assume that Appsheet is able to connect to the drive folder.
My Default ap folder is: /appsheet/data/ManyToMany-2259915
The google account (mine) used for building and accessing the app is the same used for storing the data (Google Sheets) and the same account is also the owner of the Google Drive used for storing the PDF files.

Google Drive:


File Formula (in the action):

Test for the Formula:

Path of the loaded web page showing Bad Request:
(final part)

Thanks to the official AppSheet support, I solved the issue after creating a virtual column of type “File”, named PDF File, holding the complete path + file name, and in the Open PDF action I replaced the formula with this: [PDF File].