Go to the output .apk directory:
cd /Users/patriciolopez/Repositories/almapp/uc-courses-mobile/platforms/android/build/outputs/apk/Put your release.keystore in that folder, if you don't have one (change ALIAS):
keytool -genkey -v -keystore release.keystore -alias ALIAS -keyalg RSA -keysize 2048 -validity 10000