And are you 100% sure your instance started via npx is the n8n instance listening on https://console.opendream.in/? It’d be a very unusual server setup and means that your n8n instance stops working whenever you cancel the npx command.
From your previous posts you seem to be using pm2, but I am having a really hard time understanding what’s going on your server. For example, from looking at Can i run my domain like a normal website like a WordPress website in domain.com if i am running n8n.domain.com using docker? - #19 by jaisonkerala1 it seems you’re using pm2 as the user jaison, not as the user root like in your posts in the current thread.
The previous thread also suggests you’re using an ecosystem file (in the home directory) which you’d need to update rather than specifying the environment variables as part of your command.
The npm install command most likely fails because you are using an outdated version of Node.js, so you would need to install the current LTS version 16 of Node.js before installing a new version of n8n using npm.
But again, there are a lot of things being mixed up here and you probably want to take it one step at a time.