I believe there are only 2 endpoints which I have screenshot below with sample code, hope that helps.
curl -L -H 'X-Cisco-Meraki-API-Key: <key>' -H 'Content-Type: application/json' -X PUT --data-binary '{"enabled":true,"subnet":"192.168.1.0/24","domainName":"meraki.com","sslPort":1443,"banner":"Welcome","authType":"radius","radiusServers":[{"host":"0.0.0.0","port":3000,"password":"your password"}],"dnsMode":"custom","dnsCustomNameservers":["1.1.1.1","2.2.2.2"],"splitTunnelMode":"Include","splitTunnelDestinations":["222.123.22.0/24","111.123.11.0/24"]}' 'https://api.meraki.com/api/v1/networks/{networkId}/appliance/clientVpn/anyconnectVpn'
curl -L -H 'X-Cisco-Meraki-API-Key: <key>' -H 'Content-Type: application/json' -X GET 'https://api.meraki.com/api/v1/networks/{networkId}/appliance/clientVpn/anyconnectVpn'