How can I disable the default backdrop of the fluent theme for only one window?

[lfmissonb]

I want to invoke DwmSetWindowAttribute myself to toggle the backdrop, allowing users to choose the backdrop state or select Mica or Tabbed. So how can I disable the default backdrop of the fluent theme for only one window?

[lfmissonb]

When I set ThemeMode to None, DwmSetWindowAttribute works well (I can set the backdrop to Tabbed or None).
But when I enabled the fluent theme, the backdrop was still Mica after I invoked DwmSetWindowAttribute.