Connect to OpenVPN on server but still allow SSH

I'm trying to setup an openvpn client on my Google cloud Ubuntu 18.04 VM, which will encrypt outbound traffic to my VPN provider and obfuscate my public IP.

I have done this before on other providers and it requires a custom route for allowing SSH into my server while it's connected to VPN (so return packets don't get sent out the VPN tunnel).

this is the workaround i've used before:

ip rule add table 128 from VPS_PUBLICIPip route add table 128 to VPS_PUBLICIPip route add table 128 default via DEFAULT_GATEWAY

However i can't get it working on my GCP vm. This following file runs at startup, along with a ping to my server which verifies the VPN is connecting:

ip rule add table 128 from 34.70.149.123ip route add table 128 to 34.70.149.123ip route add table 128 default via 10.128.0.1

here is the output of route -n on the server beforehand:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface0.0.0.0         10.128.0.1      0.0.0.0         UG    100    0        0 ens410.128.0.1      0.0.0.0         255.255.255.255 UH    100    0        0 ens4

any help to get ssh routing correctly is appreciated