Site to Site from UTM 9 to FortiGate 80F

There are a few articles on the internet showing configuration on both sites (like https://medium.com/@ICTFella/how-to-configure-ipsec-vpn-between-fortinet-and-sophos-firewall-ict-fella-101f5f96fc6e).

On UTM create IPsec profile including DH-Group, Lifetime and Encryption like in your screenshots.
Then create remote-gateway and add profile set to respond only, as forti will initiate connection to you WAN-IP (66.96.206.166).

Should UTM 9 to route the FortiGate Local Subnet?
As in FortiGate require to route the UTM 9 Local Subnet.

You enter FortiGate local subnet in Sophos IPsec remote networks. Route will be created automatically.

You enter FortiGate local subnet in Sophos IPsec remote networks. Route will be created automatically.

Within Remote gateway settings on UTM.