Regarding your query, you have the option to disable sidebar for the archive pages as per your requirement by following the path Admin Panel > widgets > WP Travel Archive Sidebar and remove widgets from the sidebar. You can also refer to the below-given screenshot to be more clear.
WP Travel Archive Sidebar comes from WP Travel Plugin, and you don’t have a WP Travel plugin that is why you are not being able to use see the sidebar from the widgets page.
Further, to remove the sidebar in the individual page, you can go to Admin Panel > Appearance > Pages > Individual page(edited) the page where you want to remove the sidebar and select layout with ‘no sidebar’ as shown in the screenshot below
The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.