So you want to connect via linux to your mx via client vpn?
Your read the last part of the doc?
Since Client VPN uses the L2TP over IPsec standard, any Linux client that properly supports this standard should suffice. Please note that newer versions of Ubuntu do not ship with a VPN client that supports L2TP/IP, and will therefore require a 3rd party VPN client that supports the protocol.
Note: The xl2tp package does not send user credentials properly to the MX when using Meraki Cloud Controller authentication, and this causes the authentication request to fail. Active Directory or RADIUS authentication can be used instead for successful authentication.