I’m not aware of any macOS prompts that specifically suggest WPA3.
There is a Wi-Fi weak-security message, which suggests using WPA2 AES, WPA2/WPA3 transitional, or WPA3.
To change your Wi-Fi network configuration, log into your Wi-Fi router, check for router firmware updates, and then reconfigure the Wi-Fi router for WPA2 AES, WPA2/WPA3 transitional, or WPA3.
You’ll want to ensure all of your equipment supports WPA3 before switching to that security setting. Older and IoT gear might not support WPA3.
There is one case where WPA3 is required: if you are trying to use a Wi-Fi 6E network with 6 GHz, you will need to switch to WPA3 to enable 6 GHz.
Here are the Apple: Recommended settings for Wi-Fi routers and access points - Apple Support
The Mac will adapt to the security offered by the Wi-Fi router.