How to get and update value on a specific cell?

Questions about Thunkable
1

I want to get Value of a specific cell (like A4) and Update the value of a cell in a particular row and column on spreadsheet. How can I do this? Please someone help me.

2

create as variable and when it update call the value, or you can specific with row number.

3

If you want the spreadsheet to be external to the app, you can use Google Sheets or Airtable (see this: https://docs.thunkable.com/spreadsheet).