Traffic goes past the VPN. How to set up correctly?

Question

VPN

Good afternoon,
I just moved to Linux (Ubuntu).
And I can’t configure vpn I
use Network Manager, the connection is made, but the IP does not change, the traffic bypasses vpn
The connection shows successful, plus I myself know that the vpn config is working. I used it on Windows
ifconfig
eth0: flags=4099 mtu 1500
ether 14:dd:a9:13:aa:df txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73 mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 0 (Local Loopback)
RX packets 1884 bytes 146160 (142.7 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun0 : flags=4305 mtu 1500 inet 10.8.0.6 netmask 255.255.255.255 destination 10.8.0.5 unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 100 (UNSPEC) RX packets 0 bytes 0 ( 0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 wlan0: flags=4163 mtu 1500 inet 192.168.0.136 netmask 255.255.255.0 broadcast 192.168. 0.255 inet6 fe80::2ac2:ddff:fe59:c3d9 prefixlen 64 scopeid 0x20
ether 28:c2:dd:59:c3:d9 txqueuelen 1000 (Ethernet)
RX packets 126560 bytes 95130133 (90.7 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 108381 bytes 17107272 (16.3 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
OpenVPN
feed config to Network Manager, run, shows connection established. But the IP does not
change

Answer 1

Telepaths on vacation :) Indefinitely. What kind of VPN, how to connect, what happens... The right question is half the answer.
The output of ifconfig will be useful.

Answer 2

Set the gateway for route 0.0.0.0 to the address of the vpn connection's gateway. Most likely, you will still have to add static routes to the vpn server itself through the old network.
route add default gw 10.8.0.5 tun0