Command to generate SHA –

 keytool -list -v -keystore ./android/App/debug.keystore -alias androiddebugkey -storepass android -keypass android 

Command to generate keysrore file-
go to android inside that go to app then run this

 keytool -genkey -v -keystore debug.keystore -storepass android -alias androiddebugkey -keypass android -keyalg RSA -keysize 2048 -validity 10000