\defaultfontfeatures[jetbrainsmono]
   {Extension=.otf,
    UprightFont=JetBrainsMono-Regular,
    ItalicFont=JetBrainsMono-Italic,
    BoldFont=JetBrainsMono-Bold,
    BoldItalicFont=JetBrainsMono-BoldItalic,
    Contextuals=AlternateOff
}