@_@miss.nem.one

[Unit]
Description=ai

[Service]
Type=simple
Environment=NODE_ENV=production
User=atsuchan
ExecStart=/usr/bin/npm start
WorkingDirectory=/home/atsuchan/ai
TimeoutSec=60
SyslogIdentifier=ai
Restart=always

[Install]
WantedBy=multi-user.target

みたいなので問題なく動いてる