Extending NodePool via API

Hi,
I am trying to extend an active nodePool using the following request but without any success:

curl -s "https://127.0.0.1:$RANCHER_HTTPS/v3/nodepools/$NODEPOOLID" -X PUT -H 'content-type: application/json' -H "Authorization: Bearer $APITOKEN" --data-binary '{"clusterId":"'${CLUSTERID}'", "hostnamePrefix": "'${NODEPOOL}'", "id": "'${NODEPOOLID}'", "quantity": "'${NODEPOOLNUM}'", "nodeTemplateId": "'${TEMPLATEID}'", "controlPlane":false, "etcd": false,"worker":true}' --compressed --insecure `

UI raises the following error message : Namespace parameter required.
I do not get the explanation.

Thanks and Regards