https://developer.android.com/studio/publish/app-signing.html
Build and sign your app from terminal:
keytool -genkey -v -keystore my-release-key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias my-alias
To get debug key certificate:
keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64
To get release key certificate: