FCM registering problems

[selfisekai]

throws an error while registering (with scripts/register/index.js), on request to https://fcm.googleapis.com/fcm/connect/subscribe

Error during registration
StatusCodeError: 400 - "{\n  \"error\": {\n    \"code\": 400,\n    \"message\": \"Request contains an invalid argument.\",\n    \"status\": \"INVALID_ARGUMENT\"\n  }\n}\n"
    at new StatusCodeError (/home/self/push-receiver/node_modules/request-promise-core/lib/errors.js:32:15)
    at Request.plumbing.callback (/home/self/push-receiver/node_modules/request-promise-core/lib/plumbing.js:104:33)
    at Request.RP$callback [as _callback] (/home/self/push-receiver/node_modules/request-promise-core/lib/plumbing.js:46:31)
    at Request.self.callback (/home/self/push-receiver/node_modules/request/request.js:186:22)
    at Request.emit (events.js:315:20)
    at Request.<anonymous> (/home/self/push-receiver/node_modules/request/request.js:1163:10)
    at Request.emit (events.js:315:20)
    at IncomingMessage.<anonymous> (/home/self/push-receiver/node_modules/request/request.js:1085:12)
    at Object.onceWrapper (events.js:421:28)
    at IncomingMessage.emit (events.js:327:22)
    at endReadableNT (_stream_readable.js:1201:12)
    at processTicksAndRejections (internal/process/task_queues.js:84:21)

full FCM server response:

{
  "error": {
    "code": 400,
    "message": "Request contains an invalid argument.",
    "status": "INVALID_ARGUMENT"
  }
}