index.js

const core = require('@actions/core');
const SSH2Shell = require("ssh2shell");

try {

    /* SSH input commands */
    const commands = core.getInput('commands');
    if(commands){
        console.log(commands)
        console.log(typeof commands)
    } else {
        const host = {
            server: {
                host: core.getInput('host'),
                userName: core.getInput('username'),
                password: core.getInput('password')
            },
            commands: [ssh_1, ssh_2, ssh_3, ssh_4]
        }
        /* creating new SSH client */
        const SSH = new SSH2Shell(host);
        
        /* Connecting... */
        SSH.connect(function(sessionText){
            /* Response text */
            console.log(sessionText);
            console.log("Successfully executed ssh commands!");
        });
    }
} catch (error) {
    core.setFailed(error.message);
}