The IP address for any post is in the lower left of the post, hover over the IP icon and the address will appear.

I use InfoSniper https://www.infosniper.net/ to check the IP address and then Stop Forum Spam https://www.stopforumspam.com/search to see if that IP address has been flagged for spam.

If the member is using VPN (Virtual Private Network) then this is useless because the IP address can be made to appear to anywhere. I have seen some here that show up in the middle of a large lake on the InfoSniper map.

Moderators can also look up member info and see if that member has posted from other IP addresses.

We're like Bellingcat on a very tiny scale.