Hi Keon,
Sorry for the inconvenience.
However, every theme has own UI and we have created custom theme options (CoSolu Options) and our theme only support those options that has in the theme options (CoSolu Options) based on the theme UI.
Moreover, Customize option is a default option of WordPress and there can be more options, but we didn’t provide support those options based on the theme UI.
In this issue, we will suggest you to use CoSolu Options.
Best Regards,
ThemeLooks Support Team