In fact, you're the one who made me curious, as far as I know, Meraki only works with Client VPN and Anyconnect.
In the Client VPN itself, you will use the native Windows Client (L2TP Connection) to configure the client's VPN connection.
And Anyconnect uses Cisco's Secure Client application.
Can you share a Wireguard screenshot that you commented on? If Meraki is offering this it appears to be a new feature.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.