Every application need key.properties and file with extension .jks that used for build application. First one need to create new key.properties at android folder. You can type the information about jks file in key.properties file. The information about jks file created when you create jks file. You can create jks file with this command where run at terminal: “keytool -genkey -v -keystore NAMA APPS-keystore.jks -storetype JKS -keyalg RSA -keysize 2048 -validity 10000 -alias upload”. You can change “NAMA APPS” with your apps name. After you input the data of jks question, you can type the data in key.properties. Data that need to be written is storePassword, keyPassword, keyAlias, and storeFile. storePassword and keyPassword is password when you inputted. keyAlias is alias in command sentence (like ‘upload’). storeFile is the directory of the file jks created. You need to move jks file when it created, because its created at root folder. You can move that to directory android folder.