Not able to restart node.js service from Jenkins

I've recently configured Node.js with OpenLiteSpeed from Hostinger VPS (from template). My first node app is running smoothly and that's why I move forward in configuration. I've set Jenkins for CI/CD. But from the pipeline, I'm not able to restart the node service using the following command as mentioned here
kill -9 $(pgrep -f 'lsnode')
I've also tried to integrate pm2, but stopping pm2 manually my node.js app is still being served.