curl --request POST \
  --url https://api.example.com/api/v1/cluster/join \
  --header 'Authorization: <authorization>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "csr_pem": [
    123
  ],
  "name": "<string>",
  "peer_urls": [
    "<string>"
  ]
}
'

{
  "ca_cert": [
    123
  ],
  "cert_pem": [
    123
  ],
  "cluster": "<string>",
  "member_id": 123
}