The preferred way to provide html pages is to create a (HTML)UserDialog. Html Dialogs normally define its content with JSF (JavaServerFaces). But you can put pure html content into it as well.
All the possible UI technologies of ivy are documented in the designer guide:
http://developer.axonivy.com/doc/latest/DesignerGuideHtml/ivy.userinterface.html#ivy-htmldialogs
To start with check out the examples and tutorial:
- Menu: Help -> Welcome -> Quick Start Tutorial
- or import the HtmlDialogDemos. Menu: Import -> Axon.ivy -> Ivy Archvie -> [designerDir]/applications/samples/HtmlDialogDemos.iar