@Ebakke84 Please take a look at the guide starting on page 37. When you are locally connected and bring the webpage of the IP up look at the page at the bottom left there is "change network connectivity" this is where you can set a static IP.
https://community.arubainstanton.com/t5/Instant-On-Guides/Aruba-Instant-On-1930-Installation-and-Getting-Started-Guide/ta-p/1996/jump-to/first-unread-message