Network Locator uses ArcGIS Pro Print Layouts for producing the PDF map document. You can use all of the out-of-the-box features that ArcGIS Pro Print Layouts offer.
Additionally, you can pass custom text variables to the print layout. This is done by configuring the field vertigis.network-locator.print-output.dynamic-print-elements (check Print Output Configuration)
Example:
"dynamic-print-elements": {
"orgname_value": "VertiGIS",
"request_id": "{request_id}",
"request_purpose": "{request.purpose}",
"user_company": "{user_data.attributes.company[0]}",
"user_name": "{user_data.firstName} {user_data.lastName}"
}
These text variables can then be placed on the ArcGIS Pro print layout as a Text Element, as shown below.