docs: add the jupyterhub api token need

README.md

@@ -27,6 +27,7 @@ The frontend is a simple FastAPI interface based on Swagger exposing the endpoin
 ## [rs-server-staging](charts/rs-server-staging/README.md)
 
 The staging service is a simple a simple OGC API based application for staging external data sources products.
+This application needs a Jupyterhub API Token for the moment (`dask.jupyterhub_api_token`), follow this documentation to generated one : https://jupyterhub.readthedocs.io/en/latest/howto/rest.html#create-an-api-token
 
 ## [mockup-station-adgs](charts/mockup-station-adgs/README.md)