The built lightway cannot access the Internet after being connected

[ghost]

Follow the steps below

Server settings
ip tuntap add mode tun dev helium-test
ip link set dev helium-test mtu 1350
ip link set dev helium-test up
ip addr replace 10.125.0.1 peer 10.125.0.2 dev helium-test
ip route replace 10.125.0.0/16 via 10.125.0.2

net.ipv4.ip_forward = 1
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
ufw disable

lw.out --server --protocol udp --username test --password test --server_ip 0.0.0.0 --server_port 19655 --cert certs/shared.crt --key certs/server.key --tun helium-test

Client settings
lw.out --client --protocol udp --username test --password test --server_ip 1.1.1.1 --server_port 19655 --cert certs/shared.crt --tun helium-test

I can connect to the server and ping 10.125.0.1

But my IP address hasn’t changed

I don't know what's wrong
I need your help