We can edit the theme and plugin files from WordPress. But in some case it will make problem to website. If you change any single line of the theme it will effect to the entire website. So it’s better to disable the editing of theme and plugin file from the WordPress admin panel after finishing the website development.
You can do it simply with the WordPress configuration file which in the WordPress installation path
You need to open wp-config.php file and paste the following code:
define( 'DISALLOW_FILE_EDIT', true );