Enroll Sophos FW to Defender for Endpoint

Hello,

I'm trying to enroll some network devices to Defender... I've had no issues enrolling Cisco or Aruba devices using Community String.... However, I just can't figure out how to enroll Sophs XG Firewall.

When I want to configure SNMP on Sophos, I have to provide an IP address of the snmp collector... I went back to SOPHOS tech support to check whether they have any "snmp community strings"... but looks they do not....  

Can defender be used in this cases? I've tried to configure an IP of the host on LAN that is running network scan for defender... but didn't help. So SOPHOS is asking me if:

• can the IP of the device that has network scan installed be used?
• does MS provide any public IP for Defender?