How to export e-signature data field to excel report or form report?

I created a data list and form with e-signature data field in yeeflow. When I using export function to export the data list to excel, the e-signature field not found in the excel report.

I tried to convert the data list (included e-signature field) to form report. All data converted to form report but when I use the export function to export the report, the e-signature field not found in the export field list and can’t export.

May I know how I can export the e-signature data in export file or report?

Kindly please advice. Thank you.