How to hide submenu until main link is clicked (mobile)

I have a main menu with a submenu I want to modify.
By default, under the mobile dimensions, it seems that the whole menu, including submenu is visible. What I want to do is keep the submenu hidden until the main link it clicked.

Here is a link to the site:

The link that has a submenu is “Services”.

Can anyone assist me if this is possible to modify this through wordpress or through the theme? If not, any direction on how to modify coding?

Thanks in advance.

Hi there

Hope you are having a good day and thank you for your question
Sorry but this is not possible by default without customization

Colorlib Support Team