Debian 10, Mongodb 5.0.5 - enable replication - mongod did not start - Error parsing YAML config file

Hello,
I am new in mongodb.

Did install on Debian 10.

If I enable replication

/etc/mongod.conf

replication:
replSetName: my-repl

systemctl restart mongod
systemctl status mongod

● mongod.service - MongoDB Database Server
Loaded: loaded (/lib/systemd/system/mongod.service; enabled; vendor preset: e
Active: failed (Result: exit-code) since Fri 2021-12-17 04:12:34 CST; 24s ago
Docs: https://docs.mongodb.org/manual
Process: 1383 ExecStart=/usr/bin/mongod --config /etc/mongod.conf (code=exited
Main PID: 1383 (code=exited, status=2)

Dec 17 04:12:34 mongodb systemd[1]: Started MongoDB Database Server.
Dec 17 04:12:34 mongodb mongod[1383]: Error parsing YAML config file: yaml-cpp:
Dec 17 04:12:34 mongodb mongod[1383]: try ‘/usr/bin/mongod --help’ for more info
Dec 17 04:12:34 mongodb systemd[1]: mongod.service: Main process exited, code=ex
Dec 17 04:12:34 mongodb systemd[1]: mongod.service: Failed with result 'exit-cod

How is the right syntax for replication ?

Thanks

found it, changed my config to this:

replication:
   replSetName: my-repl