Select [File] – [Save] or click the ‘Save’ 
icon to save the current page. If the page is being saved for the first time, it will be saved in “*.pgx” format in the project folder.
When you save a page, it may take a while depending on the system’s performance and the project’s size.
Hotkey: Ctrl + S, Alt + F + S
Saved files can be found in the project folder.