We have found one software suitable in our database for this conversion.
ist to pdf conversion is most likely searched by users that have files from Inspiration software and want to get these as PDF. This is possible, but for the documents / diagrams (.isf or .ins), but does not seem to be very likely for templates.
But of course if you have some specific needs with the templates and are determined that this should somehow works, it would be best to reach out to Inspiration support or online community.
Updated: October 17, 2023
IST
An ist file extension is related to the Inspiration, a program for Windows. An ist file stores template.
PDF
A pdf file extension is mainly used for Adobe Portable document format, commonly referred to as PDF. All programs that create some sort of documents or projects offer the possibility to export their format to PDF format. A free PDF viewer (Adobe Reader) is available for download from Adobe website.