I have make a webapp for data capturing. If they select a option on webapp then one data value to be auto displayed on webapp from google sheets. I tried with some codes but not succeeds. Example if i select A or B or C or D then a value will insert inside the plan box which data stored in google sheets. Please suggest.

I have make a webapp for data capturing. If they select a option on webapp then one data value to be auto displayed on webapp from google sheets. I tried with some codes but not succeeds. Example if i select A or B or C or D then a value will insert inside the plan box which data stored in google sheets. Please suggest.

I am making a web app using google sheets and google app script. My web app have an index page and an input page. There is no problem with inputting the data, however when i try to populate the data from google sheet it displayed undefined value for cells that are empty in the google sheet.