This functionality is native to spicetify-cli since v2.14
Spicetify creator plugin to show error notifications. They're the normal popup notifications, but in red.
npm install spcr-error-notificationimport { showErrorNotification } from 'spcr-error-notification';
showErrorNotification('Something went wrong');
// Alternatively, specify a duration in ms (default is 2500)
showErrorNotification('Something went wrong', 5000);