Get a VPN and you should be able to watch the Challenge Cup Games and the weekly Super League show on BBC iplayer as well https://www.bbc.co.uk/iplayerGenerally about two months haha. Another one always pops up though. Best thing to do is search 'super league' set the filters to long videos only and uploaded in the last week only. Super League ones usually stay up, but the NRL ones are a little more dicey.
If you have fibre, I'd recommend getting a VPN and using RugbyPass.com - it has everything league and union and live. It's totally legal, just not available in NZ.