Check if your wallet is locked. You need to unlock for STAKE.
You also can create the CONFIG file authorizing the Proof-of-Stake mode
File name: phantomx.conf
rpcallowip=127.0.0.1
rpcuser=
rpcpassword=
staking=1
server=1
listen=1
addnode=54.218.118.59:9340
addnode=54.218.118.59:9341
thx it seems to work when config created.