welcome to the KNIME forum community!
Could you please clarify what do you try to install? We have to key products (https://www.knime.com/software-overview):
- KNIME Analytics Platform is open source software that is used to develop data science solutions locally on a machine.
- KNIME Server is a commercial enterprise software for team-based collaboration, automation, management, and deployment of data science workflows as analytical applications and services.
The link that you shared guides through installation of the latter, but you would need an active license for it. Is that what you are interested to install and make use of?
If so, then you would need to first start the KNIME Server (it automatically start upon installation, but if you reboot of shut down the application you would need to do it again). And then you should be able to access the WebPortal of the Server by accessing
http://localhost:8080 if you run browser of the same machine or
http://<ip_address_of_KNIME_Server_machine>:8080 if you access it from another machine. Note, that in order for this to work the port 8080 should not be taken/blocked by HDP.