Support for GSync for Wayland was introduced since 525.53 release for Volta or newer GPU. There was a note in Appendix L. Wayland Known Issues :
Variable display refresh rate capabilities such as G-Sync are supported on Volta or newer GPUs with Wayland. Older GPUs are not supported.
Support for older GPUs is planned for later release and work is in progress.
To enable GSync, you need to enable VRR in your Wayland compositor. For example, KDE detects VRR support and provides options in System Settings as posted in screenshots above. There are no toggles in nvidia-settings for Wayland there.
If you have issues, please provide more details making sure you have supported GPU (which Wayland compositor are you using, GPU, monitor, driver version and running GUI applications - the more details the better).