Most times, when a power outage or something else causes the network to disconnect from your Ring device, your Ring device will automatically reconnect when the network is available again. If your Ring device needs to be manually reconnected, follow the steps in this Help Center article.
For Ring devices powered by wiring, please allow for some time for them to power back up, then check out your RSSI in the device health section of the Ring app, to ensure for optimal wifi signal.
If this concern persists, please give our support team a call at one of the numbers available here. If you are outside of the US, please visit here to see how to contact support.