Hello James,
I guess you are interested in Rd6 of the NRW-Offroad-Cup? Registration is up to the organising club, in this case MACH One Helmond. As far as I know, they usually use myrcm.ch, but there is no link for me to share yet as the race is only in August. Normally I would recommend waiting for the online registration to go live, but as you'll be coming from quite some miles away, you may want to contact them through their website:
https://www.machone.eu/contact/
I am sure Paul or one of the other guys will take care of you!
As for the licence, no licence is required for participating in any NORC series race.