How do I extract the value of one specific cell in Google Sheets?

Hello! I am new in Zapier. I need to create a database in Fibery based on documents stored in a Google Drive folder.

Each document is a spreadsheet. Each document has a header with information about the document (screenshot attached).

I need Zapier to extract the value from one specific cell and update the value in a specific attribute of an entity in the Fibery database. 

So in the end I will have a  folder with Purchase Request and database in Fibery, and in database, for example, I will have Date of Requered field, which is connected to F13 cell in the spreadsheet.

Thank you for help!