CLI Command: set encapsulation transport-mode not working

Im working on some really ooh equipment that they refuse to upgrade - FortiWifi 60A. running 3.0 MR7 Patch 10.

I'm trying to create a L2TP connection for W10 native VPN connection, but when I get to the step to "set encapsulation transport-mode" on Phase 2,  I get [command parse error before "encapsulation" Command fail. Return code -61" Any thoughts on what I'm doing wrong?

config vpn ipsec phase2
               edit dialup_p2

                 set phase1name dialup_p1
                 set proposal aes256-md5 3des-sha1 aes192-sha1
                 set replay enable
                 set pfs disable
                 set keylifeseconds 3600
                 set encapsulation transport-mode

end 

Thanks!