Available parameters and response documentation is available here

GET /lookup/lifted-over-variant/15-73027478-T-C
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=900
Content-Type: application/json ;utf-8
ETag: "5dc99387b3ad021690d6f738d1685de9dc21d5631beeddc6da4d784b64a3210b"
Vary: Accept

[
  "chr15-72735137-T-C"
]