http://mnaxv2amcoysm63cdjtjmfown65muwicvle4n3cxjxp6azsyphe4k5ad.onion
It can be an IPv4, it can be a URL/hostname that gets automatically resolved to IPs, it can be a CIDR (subnet) from 21-32 (127.0.0.0/24), it can be an IP range (127.0.0.1-127.0.0.255), it can be multiple source IPs in one attack by separating each target by comma (127.0.0.1,website.com,10.0.0.0/21).