Amazon with Govee US has the Govee Wi-Fi Water Leak Detector Wireless Water Sensor and Alarm Kit with Email, Notification, App Alerts (3 Sensors with Gateway, ‎B5040101) for $40 - 30% off coupon (click "Save an extra" box) = $28 with free shipping on $35+ or with Prime.

• Note: This is a frequently returned item on Amazon. The most common complaint is having to connect the system to a 2.4GHz Wi-Fi network rather than Bluetooth or having difficulty connecting the system to Wi-Fi.