\usepackage{fontspec}
\setmainfont{XCharter}[
    Numbers = OldStyle,
    StylisticSet = 1
]
% Load XCharter for standard text, italic, and bold
% If you need math capabilities, load unicode-math and the XCharter-Math OTF font
\usepackage{unicode-math}
\setmathfont{XCharter-Math.otf}

