import { MongoClient } from 'mongodb-4.9.1';
await MongoClient.connect(`mongodb://[::1]:27444/`); 

$ node test.mjs
node:internal/errors:477
    ErrorCaptureStackTrace(err);
    ^TypeError [ERR_INVALID_URL]: Invalid URL
    at new NodeError (node:internal/errors:387:5)
    at URL.onParseError (node:internal/url:564:9)
    at new URL (node:internal/url:640:5)
    at new HostAddress (/tmp/z/node_modules/mongodb-4.9.1/lib/utils.js:882:36)
    at Function.fromString (/tmp/z/node_modules/mongodb-4.9.1/lib/utils.js:932:16)
    at ServerDescription.get hostAddress [as hostAddress] (/tmp/z/node_modules/mongodb-4.9.1/lib/sdam/server_description.js:66:36)
    at new Server (/tmp/z/node_modules/mongodb-4.9.1/lib/sdam/server.js:31:56)
    at createAndConnectServer (/tmp/z/node_modules/mongodb-4.9.1/lib/sdam/topology.js:477:20)
    at /tmp/z/node_modules/mongodb-4.9.1/lib/sdam/topology.js:175:13
    at Array.map (<anonymous>) {
  input: 'mongodb://::1:27444',
  code: 'ERR_INVALID_URL'
}