To be able to use Natural Cycles° powered by ŌURA with an Oura Ring Gen3, you’ll need a Natural Cycles subscription and an Oura Membership.
You’ll need to have an active Oura Membership because certain data-related features aren’t available without a membership, and Oura doesn’t process the data from your ring. Without this data, Natural Cycles can’t extract the temperature trend data that would allow the NC° algorithm to identify your daily fertility status.
For any questions about the Oura Membership, please visit this link to Oura Membership FAQs.
The Oura Ring Gen2 doesn’t require an Oura Membership.