curl --request POST \
  --url https://{server-url}/chat/getBase64FromMediaMessage/{instance} \
  --header 'Content-Type: application/json' \
  --header 'apikey: <api-key>' \
  --data '{
  "message": {
    "key": {
      "id": "<string>"
    }
  },
  "convertToMp4": true
}'