You can add a Close page button which would function the same way as back.
Optionally, change the layout of the page to the one which already includes the navigation bar. Nav bars are generally added to the layouts that you configure for the application. This way you can have consistent user experience for your users.
Please note that if you’re modifying marketplace modules and later upgrade them, your custom changes may be lost. So you should extend them.
Created a new layout with back button (which is used to close the page).