Hi,
Thank you for posting in Microsoft Q&A forum.
During my search, here are some guides for your reference to manually upgrade PHP to version 7.x:
WordPress – Manual update of PHP 7.x on IIS
Using PHP Manager for IIS to setup and configure PHP
PHP on IIS Server 2019 - How do I update it?
According to your description, this issue is more related on PHP version upgrade, it's also recommended that you post a new thread in Windows IIS Forum in below link to get better support:
https://video2.skills-academy.com/en-us/answers/tags/85/windows-iis
Thanks for your time. Have a nice day!
Best regards,
Simon
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