Plesk provides native support for Server Side Include scripting for SHTML, HTML, and HTM files.
If SSI scripting still doesn't work, you might need to add the following
handler to the he
system.webServer section of your
<handlers> <add name="SSINC-html" path="*.html" verb="*" modules="ServerSideIncludeModule" resourceType="File" requireAccess="Script" /> </handlers>