POST /api/v1/signers?access_token={{access_token}} HTTP/1.1
Host: sandbox.clicksign.com
Content-Type: application/json
Accept: application/json

{
  "signer": {
    "email": "mb+singatario123@clicksign.com",
    "phone_number": "11999333445",
    "auths": [
      "email"
    ],
    "name": "Marcos Zumba",
    "documentation": "123.321.123-40",
    "birthday": "1983-03-31",
    "has_documentation": true
  }
}