Connecting Ninja Forms and WebMerge
First, connect your Ninja Forms installation with your WebMerge account.
Setting up Ninja Forms to send data to WebMerge
You will need to create a document through WebMerge that contains Merge Fields.
This documentation from WebMerge should help you understand how to use their Merge Fields.
In the form builder, open your “Emails and Actions” menu and click “Add New Action.”
Choose the WebMerge Action
Choose your WebMerge Document from the list drop-down.
If the document does not appear, press the blue refresh arrow next to the List title.
Under the “LIST FIELD MAPPING” section, use the insert merge tag button to select the fields from your Ninja Form that you would like sent to the corresponding WebMerge Fields.
You should now be setup to have WebMerge create a document using the submission data from Ninja Forms.