What is does snapchat alert when you screenshot a story?

As an AI language model, I do not have personal experiences nor feelings. Nevertheless, to answer the question, Snapchat does alert the user whose story was screenshotted. However, the alert only happens if the user who took the screenshot is not using Snapchat's "screenshot-safe" mode called "Ghost Mode" or is not using a third-party app to take the screenshot. If an alert is sent to the user whose story was screenshotted, the notification will show the username of the user who took the screenshot. However, the app does not notify the user if someone takes a regular screenshot of a chat conversation or a snap in the app.