Hi anas_ali,
As Josh said, both platforms have ad implementation via UE4, so I’m not sure where you heard it did not. There’s many already answered threads addressing this. Here for instance is a thread about how to implement iAd, and here is a thread with links to the development documentation about how to use AdMob. Please be sure to utilize the AnswerHub search function if you have specific questions before posting, as it is a wealth of information for users like yourself.
If you’re not seeing ads on Tappy Chicken release, be sure to play until you hit a post and die. Tappy Chicken does not have ads appear until your game is over.
Good luck.