Johnson, before dealing with installing/updating Applications, I suggest you open the Users Application and check how the User_Login Action is implemented. In order to view its contents:
- Open a responsive module of any Web Application
- Select the Interface tab
- Expand the UI Flows folder
- Right click on the Users dependency
- Select "Open 'Users' eSpace".
- You will be asked "Do you want to open a clone of the module?". Select "Open a clone".
- On the CloneOfUsers module, switch to the Logic tab
- Double-click on the User_Login server action
If you want to download/install/update an application, in Service Studio, go to the Environment tab and press "Install Application":

You will notice Service Studio switches to the first (black) tab, labeled "outsystems". Login using your OutSystems Community username/password and choose the application you want to install. For CryptoAPI, for instance, you can search for "crypto" and select the CryptoAPI application from the list and install/update it if needed.