In opencart version 3 there is a notification:
It is very imporant that you move the storage directory outside of the web directory (e.g. public_html, www or htdocs)
Screenshot
I tried by clicking on move button in the picture also tried manually but after trying it is giving weird errors.
You can move storage directory outside of the web directory (e.g. public_html, www or htdocs) in three ways
Assuming that you know first and second methods.Here I will explain the third method to you.
Change the following file path from both config files i.e. config.php and admin/config.php as shown below.
define('DIR_STORAGE', 'public_html/storage');
Please replace public_html to your desired path.
I hope this answer might help you.