convert Ip route command to presistent netplan

I'm totally exhausted about configuring netplan! could somebody help me to add this two command in my netplan?

I added a table mapped to a name: vpn

echo 1000 vpn >> /etc/iproute2/rt_tables

Now we have a custom table 1000 named "vpn"

ip rule add  from 10.10.10.0/24 lookup vpn

finally we add a default route for our custom table 1000 (= vpn)

ip route add default via 192.168.1.1 dev tap_tap proto static table vpn

that command work perfectly. but every reboot they are gone and I have re-enter them. I try to edit netplan but I can't! can somebody help me please?

here is my netplan which I added static Ip to my tap:

network:
version: 2
ethernets:
    ens3:
        addresses:
        - 103.144.189.141/24
        match:
            macaddress: fa:18:2e:5e:41:d1
        mtu: 1500
        nameservers:
            addresses:
            - 8.8.8.8
            - 8.8.4.4
            search: []
        routes:
        -   to: 0.0.0.0/0
            via: 103.144.189.1
        set-name: ens3
    tap_tap:
      dhcp4: no
      addresses:
        - 192.168.2.2/16

this server my domestic server (hop1) which connect to hop2 via softether lan bridgh.(tap interface named :tap_tap)

and I have openconnect server installed on this server.

when client connect to openconnect server(ocserv), ocserv assign a Ip range of 10.10.10.0/24 to client with tap device name vpns.

with that simple command I mentioned earlier I cant rout client to hop 2. but when the server reboot this chain won't work anymore till I re-enter these two code:

ip rule add  from 10.10.10.0/24 lookup vpn

ip route add default via 192.168.1.1 dev tap_tap proto static table vpn

I already read netplan examples and source-routing etc. but I can't figure it out.

Thank for all your help in advanced. Regards