1) First you need to check whether the feature "Install Apps from Unknown Source" is turned on. If it is turned off, go to settings and search for Privacy.
Within Privacy, you will find the option - "Install Apps from Unknown Source" with a toggle-switch. Tap on that toggle-switch to turn on the required feature.
(Now, you can easily install any 3rd party app in addition to Google's Playstore)
3) An installation window will appear; click on 'install now' to install the apk on your device
4) It doesn't require any additional "dependencies" to install and use this chatbot as all the dependencies are already included inside the "build.gradle" file of android's JAVA source code.
4) Now you can use the chatbot to your convenience.