Here’s some useful clear tutorial that helped me.
First watch this video and do EXACTLY as it says. Here is the link: https://www.youtube.com/watch?v=dnho...qL8iRA&index=2
the video doesn’t show you how to get the fingerprint certificate, but it tells you the steps on how to get there. After you do exactly what the video tells you, you must go to your documents to C:\Users"YourUserName"\Documents\Unreal Projects"ProjectNAme"\Build\Android. Thats where your keystore file should be in. Press and hold shift and right click on the android folder and click open “Command prompt here”. After that copy and paste this command.
keytool -exportcert -alias <your-key-name> -keystore <path-to-production-keystore> -list -v
And relapse <your-key-name> and <path-to-production-keystore> with whatever you called your keynames from the project settings. After you press enter it should tell you the (SHA1)! If you don’t understand anything reply to me.