Loop Files Operator

How can we transfer data from loop files operator to data to documents operator?

- The nested processes in loop files operator are working fine

- When I connect it to documents to data, I can't select text attribute in its properties, there isn't any option in the dropdown

- Similarly, I can't set role label

Need urgent Help

P.S. - I'm trying out the process mentioned in Chapter 14 of the book - RapidMiner - Data Mining Use Cases and Business Analytics Applications by CRC Press, edited by Markus Hofmann and Ralf Klinkenberg