After building your first workflow with Sheetgo you can always go back and add a new step to the connection you've already created. You can follow these instructions to do this in an easy way without the need to recreate your workflow from scratch.
Open the workflow and go to the list of connections.
Click on (⋮) to open the connection menu.
Click on the + icon located between the source and destination block.
Choose the Data processor you want to add and apply your conditions.
Click Save changes
Run the workflow to refresh the data and apply the data processor