ssl in traacar

how to configure ssl in traacar?

You have nothing to configure in Traccar.
Did you try to read the documentation

but in key file we have :

  public static final ConfigSuffix<Boolean> PROTOCOL_SSL = new BooleanConfigSuffix(
            ".ssl",
            List.of(KeyType.CONFIG));

https://github.com/traccar/traccar/blob/master/src/main/java/org/traccar/TrackerServer.java

Yes, is PROTOCOL_SSL.
But..., what you want to make?
Are you want to pass the device data over ssl?

yes exactly

Read the documentation Configuration file

i read but i dont know how to configure. is it possible make a example for me?