Routed IPSec Tunnel - IPSEC interface is not choosable under gateway

[RadOD]

I  am trying to setup a routed IPSEC connection almost verbatim to the guide here: https://docs.opnsense.org/manual/how-tos/ipsec-s2s-route.html without success.  Under "Step 5 - Define Gateways" it says use interface IPSEC1000, but I can only choose WAN, LAN, OPT1, etc... as the interface for the gateways.  The IPSEC interface is created and, for example, available under firewall rules.

I've been through the instructions over and over... Am I missing something that I can't choose IPSEC? Install policy is unchecked for sure.

[mimugmail]

Screenshots of P1 and P2 and interface list

[RadOD]

Among many silly errors, I had failed to set 'mode' to 'route based' in P2.

[Megachip]

Among many silly errors, I had failed to set 'mode' to 'route based' in P2.

You have to uncheck install policy as described here.