curl --request POST \
  --url https://studio.edgeimpulse.com/v1/api/{projectId}/raw-data/{sampleId}/metadata \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
  "metadata": {}
}'

{
  "success": true,
  "error": "<string>"
}