Could you please let me know which section of Install guide you are referring to?
Here is the EDC 10.5 Installation Guide.
You can visit to https://docs.informatica.com/data-catalog/enterprise-data-catalog
This is an ambari specific preq that is no longer relevant in 10.5 versions of EDC.
Unfortunately, the document has not been updated but we have documentation CR EIC-54647 to fix the same.
Thanks Srinivas for clarifying that.