✅ Can't use external font in resourcedictionary?

hey i have a resourcedictionary that defines a style for a button, and in that resourcedictionary i have a textblock that i wanna use an external font with. i imported the font in my app.xaml and it works fine everywhere else, but if i try to use it in the resourcedictionary i get thrown the error "cannot find resource named <fontname>. resource names are case-sensitive." does anyone have any idea how to fix this?