Mongo db problem on RHEL 8 / CentOS 8 _Failed to connect to 127.0.0.1:27017

Hi expert person.
I am facing a little bit problem. Please suggest to me.
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if I commend : mongo
MongoDB shell version: 3.0.14
connecting to: test
2022-06-09T15:07:57.673+0100 W NETWORK Failed to connect to 127.0.0.1:27017, reason: errno:111 Connection refused
2022-06-09T15:07:57.674+0100 E QUERY Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed
at connect (src/mongo/shell/mongo.js:179:14)
at (connect):1:6 at src/mongo/shell/mongo.js:179
exception: connect failed
You have mail in /var/spool/mail/root
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Failed to connect to 127.0.0.1:27017