Google released the April 2023 software update includes the latest security patches for Pixel Watch users. The rollout will continue over the next week in phases. Users will be notified when the OTA update becomes available for their devices.
You can use a trick to get the update faster: Open Settings/System/System Updates and click the watch icon several times. The latest Patch update comes with the build number RWDA.230114.010.G2. You can check the complete changelog which is mentioned below.