It takes about two minutes — install Apple's TestFlight app, tap the invite link below, and you're in. Works on any iPhone or iPad running a recent iOS.
testflight.apple.com/join/1ECwcyj1Apple's official app for beta testing. Free, from the App Store. Get TestFlight →
On your iPhone, tap the blue button at the top of this page. It'll open automatically inside TestFlight and show you the app.
TestFlight downloads the beta build like any normal app install — same Face ID / passcode prompt.
The app appears on your home screen with a small orange dot, marking it as a beta build. Launch it from there — or from inside TestFlight.