Enable username and password authentication on mongodb sharded cluster

Question

I have a mongodb cluster(1 mongos, mongo config replica set with 2 members, 1 shard with 3 members) and I have enabled internal authentication in config replica set. Also my backend code connects to mongos instance.

Currently, there is no authentication on login to mongos instance. Now, I want to enable username and password login on mongos.

After I run config replica set members using

security:
  keyFile: /path/to/keyfile

they work properly. But mongos does not work anymore. The command to run mongos is: sudo mongos --configdb configRepl/cfg1.example.com:27019,cfg2.example.com:27019 --bind_ip_all --port 20200 --syslog --syslogFacility local4 --timeStampFormat iso8601-local -vvvvv --keyFile /path/to/keyfile

With command above mongos will not work and exits, bu witouht --keyFile /path/to/keyfile it will not fork and work.

I have created a user before enabling authentication. All mongodb instances are version 4.4 .

I would be very thankful if ou help me.