Strongswan ipsec based vpn error

This is in swanctl.conf files for my both router and their subnet
Router 1 conf

Include config snippets

#include conf.d/*.conf
#include /var/swanctl/swanctl.conf
connections {
site_to_site {
version = 2
local {
auth = psk
id = @1.1.1.1 # Local router's public IP address
}
remote {
auth = psk
id = @1.1.1.2 # Remote router's public IP address
}
children {
sts {
local_ts = 192.168.1.0/24
remote_ts = 192.168.2.0/24
esp_proposals = aes256-sha256-modp2048
}
}
}
}

secrets {
ike-1 {
id-1 = @1.1.1.1
secret = 0987654321
}
}

Router 2 conf

Include config snippets

#include conf.d/*.conf
#include /var/swanctl/swanctl.conf
connections {
site_to_site {
version = 2
local {
auth = psk
id = @1.1.1.2 # Local router's public IP address
}
remote {
auth = psk
id = @1.1.1.1 # Remote router's public IP address
}
children {
sts {
local_ts = 192.168.2.0/24
remote_ts = 192.168.1.0/24
esp_proposals = aes256-sha256-modp2048
}
}
}
}

secrets {
ike-1 {
id-1 = @1.1.1.2
secret = 0987654321
}
}

when i connect from router 1 to router 2 i egt this error while my connect is laoded
swanctl --list-conn
plugin 'wolfssl': failed to load - wolfssl_plugin_create not found and no plugin file available
site_to_site: IKEv2, no reauthentication, rekeying every 14400s
local: %any
remote: %any
local pre-shared key authentication:
id: 1.1.1.1
remote pre-shared key authentication:
id: 1.1.1.2
site-to-site-child: TUNNEL, rekeying every 3600s
local: 192.168.1.0/24
remote: 192.168.2.0/24
root@OpenWrt:/etc/swanctl# swanctl --initiate --child sts
plugin 'wolfssl': failed to load - wolfssl_plugin_create not found and no plugin file available
[IKE] unable to resolve %any, initiate aborted
initiate failed: establishing CHILD_SA 'sts' failed

can any one help me?