Routen based IPsec vpn - unable to create an IPsec gateway

[mkonecny]

I have two OPNsense virtual appliances - one is running in Azure, the other one on prem (ESXi). Both appliances are able to create and manage policy based IPsec connections, an attempt to establisch a route based IPsec connection fails, because there is on both sides no possibilty available to create a gateway with IPsec interface (only LAN and WAN are offered). I´ve configured the following on both devices:
- Create phase 1 entry, "Install policy" unchecked
- Create phase 2 entry with two consecutive IP addresses for local and remote site
- Activating the IPsec connection (was successfully established)
- Creating a single gateway - no IPsec interface available, so there is not possible to route the traffic
- Changing the local and remote network to /30 did not help - still no IPsec interface available

Internet search brought no proper solutions for this issue - any idea?

Thanks and regards, MK