The old Blocks are not shown in Thunkable X Platform

Dear Developers,

I am building an app based on Webviewer component. I would like to create a Back and Forward button in order to go back and forward while using Webviewer. I have searched for the solutions in various topic in this Thunkable community. Finally, I found the possible way to solve this problem which is shown in the following picture.

However, when I turned back to my app. I could not find some function so that I could not do it probably. For instance, I could not find “Call Webviewer.Go Back”. “Call Webviewer. Go forward”, “When Screen … Initialize”, “When Screen…Back Press”…
The blocks was given to me are:

Could you give me the answer for this circumstance?

Additional screenshots!

The first screenshot is Thunkable Classic, the others are Thunkable X. The blocks you are looking for (WebViewer.Go Back, Screen.Back Pressed, etc.) are only available on Thunkable Classic at the moment.

Dear @Conor
Thank you, I have checked it. Is there anyway to create “Back” and “Previous” Button in the Thunkable X Platform?