To open System Settings on macOS to the Notifications panel and to a specific app's notification configuration in Swift:

let notificationsPath = "x-apple.systempreferences:com.apple.Notifications-Settings.extension"
let bundleId = Bundle.main.bundleIdentifier
if let url = URL(string: "\(notificationsPath)?id=\(bundleId ?? "")") {
    NSWorkspace.shared.open(url)
}