curl --request GET \
  --url https://mpc-client.portalhq.io/v1/presignatures \
  --header 'Authorization: Bearer <token>'

{
  "presignatures": [
    {
      "id": "<UUID>",
      "expiresAt": "2025-03-18T10:00:00Z",
      "curve": "SECP256K1",
      "managed": true
    }
  ]
}