Custom 404 Page
Since Ewebot theme version 2.5.9 those settings moved to WordPress customizer. Here you go Appearance -> Customizer -> Theme options -> General.
Deprecated:
Since theme version 2.4.2 you can create a custom 404 error page in Elementor and assign it in the theme options panel.
First, create a standard page in Elementor using GT3 Elementor custom widgets or default ones.
Once your custom 404 error page is ready, please open Theme Options Panel -> General -> Select 404 Page and choose any page from the list and save changes.
That’s all.