The apk file of KingoRoot downloaded directly from the server of Kingo cannot be permitted to install on your device unless you allow the installation from ” “Unknow source”
Maybe only some apps from Google Play or Samsung Apps can be installed on your device. Install Blocked: Settings > Security > Unknown sources > Check the box and allow. Whatever it might be, follow the instructions provided.
You may encounter some issues when you install the tool. Step 2: Install the apk file of KingoRoot.