I created Forge viewer version 7 in my own website. I'm trying to add markups like the one shown in Autodesk website (see picture below);
Are there any tutorial for creating markups tool like this? I found some but they are either outdated version or incomplete. Please suggest, thank you.

The easiest approach would be to use the built-in
MarkupsGuiextension which provides UI to create markups:Then a button will appear in the toolbar to trigger the extension:
Alternatively you can come up with your own UI and leverage the
MarkupsCoreextension which is also built-in to programmatically switch between markup tools and even create markups programmatically, see documentation hereYou can either call or extend these to create your own custom extension.