The following guide shows you how to update and reconnect your Ring Doorbells Wi-Fi details. The process is pretty similar between all Ring Doorbell models.
Open the Ring app on your phone or tablet, press the menu icon in the top left and then tap devices.
Your list of Ring devices will show, select your doorbell which is no longer connected to wifi. Then tap device health.
If your Ring device is offline, it will say "Offline" under the Network header. To reconnect your doorbell to a wireless network, tap on 'Reconnect to Wi-Fi'
Follow the on screen instructions to complete the process. If you have trouble connecting, you may want to take a look at the following Ring support article: https://support.ring.com/hc/en-gb/articles/216536843-What-to-Do-if-Your-Ring-Video-Doorbell-Goes-Offline