You can find Formtools at: https://formtools.org
From the site:
I have an example using the Default form from Form Designer that works with Formtools:
https://multisite.cloudaccess.host/Form Designer 1
A ZIP file for the example is at:
https://multisite.cloudaccess.host/Form Designer 1.zip
The ZIP file contains:
1. The Form Designer Project File. The only modifications made to this project file template was to add names to all form input fields.
2. A printout of selected form submissions exported from the submission database.
3. An Excel spreadsheet of the same selected form submissions exported from the submission database.
2. and 3. were made from modules in Formtools itself.
Install Formtools then...
To process your own form, carefully read the documentation and follow the steps exactly to process your own External form.
Good Luck, if you choose to go this way.