My blueprint setup is as simple and as similar to the unreal engine documentation. As I mentioned, it works perfectly in 4.14.3, as in 4.14.3, I do not have to change or add in code lines to the defaultengine.ini as previous version. On 4.14.3 I just edited the iOSEngine.ini as like I said above, then it works. Once project open in 4.15, nothing happen in iAP. Thanks.