You can use the availability endpoint to get freebusy and schedule data of any user.
In your request body, it is essential to include at least one of the following properties: username, userId, or teamId. Please note that your request won't be processed unless at least one of these properties is provided. Choose the most suitable property based on the context of your request. The teamId takes precedence if all of them are provided as part of the request.
Get a user's or team's availability