How do I install the Melbet app outside the App Store?

My mom recently got into betting a bit (don’t ask ), and she asked me to install the Melbet app on her iPhone. I thought it would be easy, just go to the App Store and done — but nope. The app doesn’t even show up for us. We live in a country where, apparently, the download page is blocked. I remember someone here saying they got around this somehow by changing regions or using a direct link? I’d love to know what worked for you, ‘cause she’s now bugging me daily about it.