i have menu with sub menus and I want the sub menu to be displayed when I open the website, then it will only close when I click

this is my website http://saifalburhan.weinnobite.com/ then the menu named shop by categories has sub-menus I want it to be displayed when I open my website and it only close when I click it. do you have any idea CSS code or what the other way to display it is?

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