How to use the autorest.initialize function in autorest

async function build() {
    // use local version of autorest extensions instead of global machine versions
    await autorest.initialize("./node_modules/@microsoft.azure/autorest-core");

    const autorestInstance = await autorest.create();
    autorestInstance.AddConfiguration({
        "nodejs": {
            "package-name": "vscode-azurekudu",
            "license-header": "MICROSOFT_MIT_NO_VERSION",
            "add-credentials": "true",
        },
        "title": "KuduClient",
        "input-file": path.join(__dirname, 'swagger.json')
    });
    autorestInstance.Message.Subscribe((_, msg) => {
        if (msg.Channel !== 'file' && msg.Text) {
            console.log(msg.FormattedMessage || msg.Text);
        }
    });