Can't create SSTP VPN connection using Python 3 dbus about network-manager-sstp HOT 1 CLOSED

import dbus
from pprint import pprint

bus = dbus.SystemBus()

ssn = "org.freedesktop.NetworkManager"

sysproxy = bus.get_object(ssn, "/org/freedesktop/NetworkManager/Settings")
settings = dbus.Interface(sysproxy, ssn + ".Settings")
c = settings.ListConnections()[0]
#pprint(settings.ListConnections())

for conn in settings.ListConnections():
    connproxy = bus.get_object(ssn, conn)
    conn = dbus.Interface(connproxy, ssn+'.Settings.Connection')
    pprint(conn.GetSettings())
    print()

import dbus
import uuid
import os

bus = dbus.SystemBus()

ssn = "org.freedesktop.NetworkManager"

sysproxy = bus.get_object(ssn, "/org/freedesktop/NetworkManager/Settings")

settings = dbus.Interface(sysproxy, ssn + ".Settings")

s_vpn = dbus.Dictionary({
            'ca-cert' : '/usr/local/share/ca-certificates/my-cert-chain.pem', 
            'user' : 'usernmae', 
            'refuse-eap': 'yes', 
            'refuse-chap': 'yes', 
            'gateway' : 'vpn.example.com', 
            'domain' : 'EXAMPLE', 
            'refuse-pap' : 'yes', 
            'password-flags' : '0', 
            'proxy-password-flags' : '0', 
        })

s_secs = dbus.Dictionary({
             'password' : 'password',
        })


s_con = dbus.Dictionary({
    'id': 'Example SSTP',
    'type': 'vpn',
    'uuid': str(uuid.uuid4()),
    'permissions': ['user:'+os.environ['USER']],
    'autoconnect' : False,
})

s_ip4 = dbus.Dictionary({'method' : 'auto'})

s_ip6 = dbus.Dictionary({
    'method' : 'ignore',
    'ip6-privacy' : False,
    'addr-gen-mode' : 1, # 'stable-privacy' ?
})

con = dbus.Dictionary({
    'connection': s_con,
    'vpn': dbus.Dictionary({ 
                'data': s_vpn,
                'service-type' : ('org.freedesktop.'
                                  'NetworkManager.sstp'),
                'secrets' : s_secs,
                }),
    'ipv4': s_ip4,
    'ipv6': s_ip6,
})

settings.AddConnection(con)