This command prompts you for passwords for the keystore and key, and to provide the Distinguished Name fields for your key. It then generates the keystore as a file called my-release-key.keystore.
The keystore contains a single key, valid for 10000 days. The alias is a name that you will use later when signing your app, so remember to take note of the alias.
+On Mac if you not sure where is your jdk bin folder is then perform the following command to find it,
+$ /usr/libexec/java_home
+it will output the directroy of jdk which looks like this,
+/Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home
+then navigate to that directory by the following command,
+$ cd /Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home/
+Now you can perform the keytool command with sudo permission as shown below,
+$ sudo keytool -genkey -v -keystore my-release-key.keystore -alias my-key-alias -keyalg RSA -keysize 2048 -validity 10000
Note: Remember to keep your keystore file private and never commit it to version control.