curl -X POST http://127.0.0.1:8000/process
-H "Content-Type: application/json"
-d '{"background": "http://127.0.0.1:8000/images/background.png", "overlay": "http://127.0.0.1:8000/images/overlay.png"}'
curl -X POST http://127.0.0.1:8000/process
-H "Content-Type: application/json"
-d '{"background": "http://127.0.0.1:8000/images/background.png", "overlay": "http://127.0.0.1:8000/images/overlay.png"}'