Hi everybody, I have a problem of search box

It must be in the included in the code somewhere. Most search forms will have a search.php or some other variation of that name if it is a custom search (located in the root of your theme).

**EDIT: ** off the back of our short conversation below.

You have used WooCommerce to arrange your products. This means you will want to edit the product search form. This will be located within your /plugins/woocommerce folder the file most likely called product-searchform.php.

You shoulnt edit the form here though as when you update woocommerce you will delete your changes.

You will want to create a folder called woocommerce in the root of your theme. yourtheme/woocommerce. Making a copy of the searchform.php and editing it within this newly created folder.