When making SEO or Social Media Sharing changes to the website it is possible to take a look at the website source code to identify if these changes were properly made. To see these changes, visit the page, right click anywhere on the page and select View Page Source.
Another option to access the source code of a page is by pressing "Ctrl" and "U" simultaneously. On Safari – The keyboard shortcut is Option+Command+U.
Every web browser allows to do this easily.
Once the admin / collaborator knows how to view the source code, it needs to know how to search for things in it. Usually, the same search functions use for normal web browsing apply to searching in the source code. Commands like CTRL + F (for Find) will help to quickly scan the source code for important SEO elements.
This is the Source Code of the Website: