mongo
show dbs
use admin
db.createUser({user: "monitoringv5",pwd: "monitoringv5", roles: [ { role: "userAdminAnyDatabase", db: "admin" }, "readWriteAnyDatabase" ]})
exit
sudo nano /etc/mongod.conf
append this line :
security: authorization: enabled
sudo systemctl restart mongod
References
https://www.digitalocean.com/community/tutorials/how-to-secure-mongodb-on-ubuntu-20-04