Help requested – Highbrow Unlimited Review

This rating is a placeholder: if I get a reply from the devs and can access the content, I’ll give it an honest review. If not, it stays a 1. Looks like a fun app for my child, but I can’t access the free trial. It says, “Grown-ups only! To access, please enter.” Below that is a row of numbers that remains partially obscured (the bottoms of the numbers are clipped). I can select 3 numbers, and then the field is erased. Presumably, the intent was to show a simple math problem and then have the adult input the 3-digit answer. I see no math problem and only part of the numbers below. I’m using an 8+ with iOS v.11.3. I tried the obvious stuff like restarting the app and attempting to change the orientation to portrait. Advice is needed, devs.
Review by Appappluvr on Highbrow Unlimited.