Note:
      
        
          The keytool command might not be in your path—it’s
part of Java, which is installed as part of
Android Studio.  For the concrete path,
run flutter doctor -v and locate the path printed after
‘Java binary at:’. Then use that fully qualified path
replacing java (at the end) with keytool.
If your path includes space-separated names,
such as Program Files, use platform-appropriate
notation for the names. For example, on Mac/Linux
use Program\ Files, and on Windows use
"Program Files".
        
        
          The -storetype JKS tag is only required for Java 9
or newer. As of the Java 9 release,
the keystore type defaults to PKS12.

Reference the keystore from the app

Create a file named [project]/android/key.properties
that contains a reference to your keystore: