Go to your home screen and the Delta app should start downloading.
Once Delta finishes downloading, click on it. If you get an integrity error, check the "Notes" section.
Go to System Settings → VPN and Device Management. Trust the Delta app under the certificate name and restart your device.
You're done! Whenever you get a pop-up asking you to complete two tasks, just click the two blue buttons and wait 30 seconds; the pop-up will disappear.
Direct Install is managed by a third-party (Skibidi Tech). This means that updates can take longer.
Direct also has more advertisements in-game than the IPA method (which only shows them right before you start the key system).
If you get upgrade/integrity errors, uninstall Delta and reinstall it. If you still get upgrade/integrity errors, sideload Delta with its IPA file
or wait for Skibidi Tech to update Direct. He usually makes a video whenever he updates/changes the certificate used for Delta,
so subscribe to his YouTube channel and keep your notifications on.