curl --request PUT \
  --url https://api.tenbytecloud.com/v1/network/network/{network_uuid}/default \
  --header 'apikey: <api-key>'

{
  "name": "network3",
  "uuid": "4e5eadd3-8b11-4c34-812a-2cf97120b628",
  "is_default": true
}