How to set the width of Flatmenu manually

Hi, I am creating a combobox-like widget and I am using wx.lib.agw.Flatmenu for the dropdown menu part.

However, I would like set the width of the flatmenu to be the same width as the button which pops it up as it looks odd otherwise.

How could I do this? Any suggestions anyone? :grinning_face_with_smiling_eyes:

Screenshot 2021-06-25 160836