How to run an Expokit project on a Mobile / Emulator for development?

I had a project Made In Expo, but I ejected it using Expokit, which creates the folders / android and / ios, I can generate the apk however I can not emulate on my mobile for development. The command I use to build the apk is gradlew assembleRelease, i tried to use react-native run-android but gave error. Any suggestions on how to run a project on My Mobile / Emulator for development? Follows the image with the error after react-native run-android:

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Author: Matheus Silva, 2018-12-04