unable to add single page on concrete5

Question

I am unable to add a single page on a concrete5 site. Please check the screenshot: https://prnt.sc/hns5p7

Also please check the below screenshot:
https://prnt.sc/hns6oa

In this folder I have added a view.php file and print a custom message for now, like "Test". Now I am trying to add a single page from Themes & Page Types > Single Pages. Its showing the same error. I don't know why its showing this error. Also I have followed below link to add a new single page.

https://www.concrete5.org/community/forums/customizing_c5/creating-dashboard-page-tutorial

Answer 1

There's a page in the concrete5 documentation that explain how to create single pages: see https://documentation.concrete5.org/developers/working-with-pages/single-pages