This is the documentation for the 19.02 version. Looking for the documentation of the latest version? Have a look here.
tnsr(config)# ipsec tunnel 0 tnsr(config-ipsec-tun)# local-address 203.0.113.2 tnsr(config-ipsec-tun)# remote-address 203.0.113.25
ipsec tunnel <n> command changes to IPsec tunnel mode, denoted by
ipsec-tun in the prompt. The identifier number for tunnel entries starts at
0 and increments by one. To determine the next tunnel number for a new
ipsec tunnel ? and TNSR will print the existing tunnel ID numbers
as well as the next one available.
To start configuring the IPsec tunnel, first define the endpoints. The
local-address command defines the IP address used by TNSR for this IPsec
remote-address defines the opposing router.