Build Failed after detach

Hi there!
I’ve created a new detached app with expo. I’ve followed instructions on react native web site, but unfortunately I’m not able to create (build) an .apk file. What I’ve tried is “Generating Signed APK” guide (Publishing to Google Play Store · React Native); after procedure, I’m able to find the apk, but when I run it on my device the app stops (maybe it crashes)…

Any help? Thank you.