You won’t find any PHP in the Wix and Corvid resources. All of our code is Javascipt.
If you want to expose an API from your Wix site, see this example and the referenced resources:
Expose and Access Site APIs
Use MyApi and MyApiClient to expose and access external APIs.
If you are interested in accessing an external database, then see the article External Database Collections .
IMHO you would be better off with a Wix database where you can easily use dynamic pages to display all of your content.