I tried to follow https://casept.github.io/post/wireguard-server-on-openwrt-router, as it is most recent article found, and also because luci interface is broken for Turris OS packages (datatypes.lua).
But for some reason, when I configured both server/peer parts on Omnia, I lost my internet connectivity on router 
I have OpenVPN ono iface 10.0.8.x, tried add wg to the 10.0.10.x
firewall (I dont think is relevant)
> config zone
> option name 'lan'
> list network 'lan'
> list network 'vpn0'
> list network 'wg0'
> list network 'wifi'
> option input 'ACCEPT'
> option output 'ACCEPT'
> option forward 'ACCEPT'
> config redirect
> option name 'Router Wireguard xxxxx->1234'
> option target 'DNAT'
> option src '*'
> option proto 'udp'
> option src_dport 'xxxxx'
> option dest_port '1234'
Network:
> config interface 'loopback'
> option ifname 'lo'
> option proto 'static'
> option ipaddr '127.0.0.1'
> option netmask '255.0.0.0'
>
> config globals 'globals'
>
> config interface 'wan'
> option ifname 'eth1'
> option proto 'static'
> option ipaddr 'public IP'
> option netmask '255.255.255.252'
> option gateway 'public IP'
> option peerdns '1'
> option dns 'DNSs'
>
> config interface 'wan6'
> option ifname '@wan'
> option proto 'dhcpv6'
> option reqaddress 'force'
> option reqprefix '63'
> option noserverunicast '1'
>
> config interface 'lan'
> option ifname 'eth0 eth2'
> option force_link '1'
> option type 'bridge'
> option proto 'static'
> option netmask '255.255.255.0'
> option ipaddr '10.0.5.1'
> option ip6assign '64'
>
> config interface 'wifi'
> option proto 'static'
> option ipaddr '10.0.6.1'
> option netmask '255.255.255.0'
> option delegate '0'
>
> config interface 'wifi_guest'
> option proto 'static'
> option ipaddr '10.0.7.1'
> option netmask '255.255.255.0'
> option delegate '0'
>
> config interface 'vpn0'
> option ifname 'tun0'
> option proto 'static'
> option ipaddr '10.0.8.1'
> option netmask '255.255.255.0'
> option ip6assign '64'
>
> config switch
> option name 'switch0'
> option reset '1'
> option enable_vlan '1'
>
> config switch_vlan
> option device 'switch0'
> option vlan '1'
> option ports '0 1 2 3 5'
>
> config switch_vlan
> option device 'switch0'
> option vlan '2'
> option ports '4 6'
>
> config interface 'wg0'
> option proto 'wireguard'
> option private_key 'private server key'
> option listen_port '1234'
> list addresses '10.0.10.1/24'
>
> config wireguard_wg0
> option public_key 'public client key'
> option route_allowed_ips '1'
> list allowed_ips '0.0.0.0/0'
> list allowed_ips '::/0'
> option persistent_keepalive '25'
> option description 'Jirka'
No other changes done (DHCP etc.). I dont try to enable wg IPv6 yet, I just tried to enable basic VPN with access to the LAN resources. What I am missing here? 