Totally unable to use Beryl at Sheraton Amsterdam Airport (a Marriott Bonvoy property) which has no password but requires user to accept hotel conditions before granting access. Blocked from reaching content page using Beryl. I had no problem logging in with no password from iPhone and iPad, but obviously insecure. This is a huge international hotel chain and something I think you should address quickly…
Search here for captive portal. There will be a bunch of posts with various ways to trigger the page. Try going to cnn.com and see if that triggers the portal page.
Otherwise, login from the iPhone, copy the MAC address of the phone down, use MAC Clone on the Beryl and then try connecting.
When you open a browser to go to the portal, do not click on any saved URLs, as they are almost certainly HTTPS, which doesn’t work with some portals. Type in: http://1.1.1.1 and try that.
Beryl did connect to Marriott after I disable DNS Rebinding Attack Protection, and brought up a blank page I took to be the portal but with an error message.