[Metricbeat]About the configuration of mongodb module to connet a mongodb server with SCRAM-SHA-256

I want to use metricbeat to monitor a mongodb(4.0) server with SCRAM-SHA-256

But the metricbeat service shows:
Jul 31 09:45:55 Perf-7151 metricbeat[19520]: 2019-07-31T09:45:55.724+0800 ERROR mongodb/mongodb.go:98 Error establishing direct connection to mongo node at [localhost:27019]. Error output: server returned error on SASL authentication step: Authentication failed.
Jul 31 09:45:55 Perf-7151 metricbeat[19520]: 2019-07-31T09:45:55.724+0800 INFO module/wrapper.go:244 Error fetching data for metricset mongodb.dbstats: error creating new Session: server returned error on SASL authentication step: Authentication failed.

Tried as fllowing:

  1. hosts: ["localhost:27019"]
    username: admin
    password: admin
  2. hosts: ["mongodb://admin:admin@localhost:27019/admin?authMechanism=SCRAM-SHA-256"]
  3. hosts: ["mongodb://admin:admin@localhost:27019/?authSource=admin?authMechanism=SCRAM-SHA-256"]
  4. https://github.com/elastic/beats/pull/12867
    hosts: ["localhost:27019"]
    username: admin
    password: admin
    mechanism: SCRAM-SHA-256

None of them worked!

If there is an answer that what is the correct way to access mongodb server with SCRAM-SHA-256?
Or does it supported?

metricbeat version

metricbeat version 7.2.0 (amd64), libbeat 7.2.0 [9ba65d864ca37cd32c25b980dbb4020975288fc0 built 2019-06-20 15:07:31 +0000 UTC]

Thanx,
Yuewu