hey'it's me

I've been trying to flash my ducky to the twin duck but my ducky seemingly will not enter DFU mode. I tried it on both windows 10 and Ubuntu but neither will work has anyone else had this problem and fixed it?

Every time I try to use java -jar duckencode.jar I keep getting the error unable to access jarfile duckencoder. I've tried running as an administrator but that doesn't work and I've also updated java. Sorry I'm a nub. \: