I was thinking of just export to text file elsewhere and use the fetch feature of camera site.
Put text file of data somewhere, treat it, and pluck it?
Can I utilize RPI?
There is no problem to export data from WiFiLogger as JSONs via HTTP PUT, or MQTT.
You have two options:
1 old - wflexp.json
2 new - PHP&MySQL JSONs set.
You can turn on export to own PHP script which will take JSON file parse it, take it what you need and send this data in other shape to other web site.
I will provide PHP to put data to MySQL, but same JSONs can be change in PHP to any other format.
On the other hand data from MySQL can be exported to other web site as well. I have no scripts to read data from MySQL yet, but there is no technical issue with that.
About Raspberry Pi. If you have WWW hosting with PHP, then there is no reason to add Raspberry Pi to this system.
Put own PHP to your WWW hosting and setup WiFiLogger to send wflexp.json there.
I can provide you very simple PHP example how to save JSON to hard drive.
Also I can send you current PHP&MySQL files.