The script is available for download from https://gallery.technet.microsoft.com/FTP-with-SSL-creation-if-ce02c21d.
You can also use Microsoft Script Browser for Windows PowerShell ISE to download the sample with one button click from within your scripting environment.
The sample powershell script does the following: 1. Checks if the required FTP site already exits 2. If it exists it will show the suitable message. 3. If it doesnt exist it will create the IIS FTP website named "testftp" with SSL certificate
You can find more All-In-One Script Framework script samples at https://aka.ms/onescriptingallery