App crashes when there is no internet connection

I’m using AdMob services and Unity In-App Purchase with Analytics services. If I’m not wrong those are the causing this crash. Can i set up the app to work without internet connection or can I check to internet connection before app crash and informing the user?

I fixed it with checking is network connection available before ad request.

The most stable internet control method is at this link → https://answers.unity.com/questions/567497/how-to-100-check-internet-availability.html?childToView=744803#answer-744803