I can't duplicate the problem that you're reporting. I installed the nodejs plugin, configured a node installer that I named "node-14.13.1" and then defined a pipeline job that uses the following script:

pipeline {
    agent {
        label '!windows && !s390x && !ppc64le'
    }

    stages {
        stage('Build') {
            steps {
                nodejs(nodeJSInstallationName: 'node-14.13.1') {
                    sh 'npm --version'
                }
            }
        }
    }
}

That declarative pipeline script was taken from the nodejs plugin online documentation with a modification of the agent definition to avoid agents in my environment that are not supported by the nodeJS installers.

I saw in your attached pictures that you were using node 12.18.4. I created a new installer for node 12.18.4, modified the job to use that installer, and confirmed that it worked as well.

You'll need to provide enough details that will allow others to duplicate the issue. See "How to report an issue" for the types of details that are most often needed.

i have used above pipeline which is given in your comment but still same error exist. which file i need to look for solve that issue. 

i have Intel(R) Xeon(R) CPU E31230 @ 3.20GHz

I can't duplicate the issue you're reporting. You'll need to provide enough details that will allow others to duplicate the issue. See "How to report an issue" for the types of details that are most often needed.

NodeJS 12.18.4 for linux env and 32bit CPU architecture does not exists.
https://nodejs.org/dist/v12.18.4/

The CPU i386 as been recognized from the JVM. This means that you are running on 32bit architecture PC or the JVM that execute the jenkins agent/master is 32 bit. So change the JVM to a 64bit JVM, the PC 64bit ready or look for a NodeJS version supported by your PC.