You cannot “Run this module only”. The “Data” you put in from the Output Bundle in the Get a file module is only a truncated preview of the full file.
You cannot individually run a single module if you don’t have example input data values for each required field, which you must input into the dialog box when you manually run a single module. This is because when you run a module directly, the mapped variables in the fields are null (do not contain any value).
Instead, try running the full scenario by clicking the “Run Once” button:

For more information, see these duplicate questions previously asked and answered by other community members:
- Missing Values While Processing Google Forms Data
- Not able to use webhook data
- Make not recognizing value of a variable
Hope this helps! If you are still having trouble, please provide more details.
— @samliew