Choose Gateway (Group) for Wireguard Connection itself running on the OPNSense

[steven90]

Trying to figure this one out for ages.
How can i choose which Gateway / Gateway Group is used for a VPN Connection itself (Wireguard) running on the OPNSense.

For example if i have two physical Gateways (lets say DSL and 5G) and two wireguard tunnels running on the opnsense (vpn1 and vpn2), how can i force vpn1 to use the 5G gateway / upstream for its connection and how can i force vpn2 on the dsl?

Thanks