Available parameters and response documentation is available here

GET /lookup/10190091015942290001?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json ;utf-8
ETag: "388528a7bd9e1163424272f749554ab0a315d848157daef5069d47e175540fe2"
Vary: Accept

{
  "chromosome": "chr9",
  "alt": "A",
  "ref": "G",
  "pos": 101594229,
  "variant_id": "10190091015942290001",
  "variant_type": "SNV",
  "cytobands": "9q22.33",
  "publications": {
    "publications": [],
    "genes": []
  }
}