Hi Ahmed,

Unfortunately there are no settings for this. The category pages are automatically generated by WordPress on the fly.

If you would like making changes to these category pages you're better off by manually recreate category pages for your projects by using default pages under the "Pages" tab.

This can be done on the following way:

1. Go to Appearance -> Customize -> Post Types -> Projects
2. Uncheck the "Enable the project categories" checkbox and save the settings
3. Go to Settings -> Permalinks
4. Scroll to the bottom of the page and press the save button
5. Go to the "Pages" tab
6. Create a new page with the name of one of your project categories
7. Set your main project page as "Page Parent" within the "Page Attributes" panel on the right side
8. Add a "QT: Projects" element to the page and edit this element
9. Select the project category you would like to display on this page
10. Save the page

You can repeat step 6 till 10 for other project categories. On this way you have full control over the layout of the page and can add content/sidebars to this page.