How to get and AWS SSM parameter using SDK

getParameterFromSystemManager.js

const AWS = require('aws-sdk');
const ssm = new AWS.SSM();

const getParameterFromSystemManager = async (key, isEncrypted = true) => {
    
    // Fetches a parameter from SSM parameter store.
    // Requires a policy for SSM:GetParameter on the parameter being read.

    const params = {
        Name: key,
        WithDecryption: isEncrypted // "true" if is a SecureString, otherwise must be "false"
    };
    
    try {
        return ssm.getParameter(params).promise();
    } catch (err) {
        throw new Error('Failed to get parameter from AWS', err.stack);
    }
}