curl --request GET \
  --url https://api.magne.app/v1/keys/bundles/{userId} \
  --header 'Authorization: Bearer <token>'

{
  "deviceId": "<string>",
  "identityKey": "<string>",
  "signedPreKey": {
    "keyId": 123,
    "publicKey": "<string>",
    "signature": "<string>"
  },
  "oneTimePreKey": {
    "keyId": 123,
    "publicKey": "<string>"
  }
}