A Map Series has the ability to create a separate page for each feature:
To be able to leverage this in your web page, you could create a geoprocessing service. The geoprocessing service would take parameters, such as the extent and then create a map series. The resulting pdfs could then be zipped up and returned as the result of the geoprocessing service.
You will need access to ArcGIS Enterprise to host the geoprocessing service and also do some coding in Python.