How to use the camel-ssh feature to help me manage remote services such as the nginx reload command

[??????]

I have a need


First I sync the file to the web server via camel-sftp


After transferring the file, do the nginx -s reload command on each server.


My code is as follows


But why pollcomand doesn't work


from("file:I:/workProject/java/xxxx/luaFiles/").multicast().to("direct:a", 
"direct:b").end().to("direct:c");
        
from("direct:a").to("sftp://root@192.168.56.14/xxxx/controllers/gen/?password=root&stepwise=true&runLoggingLevel=TRACE&throwExceptionOnConnectFailed=true&idempotent=true";);
        
from("direct:b").to("sftp://root@192.168.56.14/?password=root&stepwise=true&runLoggingLevel=TRACE&throwExceptionOnConnectFailed=true&idempotent=true";);
        
from("direct:c").to("ssh://root:root@192.168.56.14?poll-command=reboot%0A&pollCommand=nginx
 -s reload %0A").log("done ????${body}");


how to 
please help 
thanks!!!