Some links provide an APK file. An iPhone cannot read an Android file. If you download an APK on an iPhone, you have downloaded a useless, potentially dangerous file.
Mob Entertainment usually ports chapters to mobile months or years after the initial PC release. Optimization for mobile processors takes significant development time due to the game's high graphical demands. ⚠️ The Dangers of "Free iOS Download" Websites Poppy Playtime Chapter 3 Free Download Mobile Ios
Many fake sites ask you to go to Settings > General > VPN & Device Management to install an "untrusted enterprise certificate." These certificates are designed to bypass Apple’s security, but once installed, the person who made the profile can remotely control parts of your device. Some links provide an APK file
Even if a fan-made port exists, it is often unoptimized, leading to crashes and potential damage to your device’s software. How to Play Poppy Playtime on Mobile via Cloud Gaming Mob Entertainment usually ports chapters to mobile months
Search for "Poppy Playtime Chapter 3" and ensure the publisher is Mob Entertainment.