Probably DAZN in Italy
I think he'd need a VPN still, but this looks like this best (most legal) solution, depending if he has DAZN already or minds getting a subscription.
Additionally, DAZN users in other countries where the service is available, such as Japan and Italy, should be able to use a VPN to connect to the live broadcast in DAZN US or DAZN Canada
https://www.comparitech.com/sports-streaming/watch-joshua-povetkin-online-live-stream/#gref
Any Boxing fans from Italy on here? I'm wondering if there's any TV station showing the Joshua Vs Povetkin fight tonight? I'm currently in Italy.
Ha, well. I can't say for sure (cos I don't live there) but I'm assuming it would have been carried by Sky Italy and they don't seem to have it on regular schedule (though interestingly you can catch international judo at about the same time it would have been) or on demand best I can tell. You may have to catch a stream.
http://guidatv.sky.it/guidatv/sky-on-demand/sport-e-calcio.html
http://guidatv.sky.it/guidatv/grid.html?category=sport
You might be able to order online from sky box office but you may run into problems with not being in the UK - definitely check before you order (though a VPN could circumvent this issue if you use one):
https://www.sky.com/boxoffice/