\documentclass{article}
\usepackage{parskip}
\usepackage{hologo}% to access the XeTeX logo via \hologo{XeLaTeX}
\usepackage{fontspec}
\setsansfont{Asap}[
    Path=./AsapFontFiles/,
    Scale=0.9,
    Extension = .ttf,
    UprightFont=*-Regular,
    BoldFont=*-Bold,
    ItalicFont=*-Italic,
    BoldItalicFont=*-BoldItalic
    ]
\setmainfont{Brygada1918}[
    Path=./BrygadaFontFiles/,
    Extension = .ttf,
    UprightFont=*-Regular,
    BoldFont=*-Bold,
    ItalicFont=*-Italic,
    BoldItalicFont=*-BoldItalic
    ]
\setmonofont{JetBrainsMono}[
    Path=./JetbrainsFontFiles/,
    Scale=0.85,
    Extension = .ttf,
    UprightFont=*-Regular,
    BoldFont=*-Bold,
    ItalicFont=*-Italic,
    BoldItalicFont=*-BoldItalic
    ]
\title{Using Google Fonts with \hologo{XeLaTeX}}
\author{Overleaf}
\date{September 2023}
\begin{document}
\maketitle
\section{Introduction}
The following lists demonstrate the various fonts we have uploaded.
{\sffamily This is the Asap sans serif font: 
\begin{itemize}
    \item {\itshape now in italic}
    \item {\bfseries now in bold}
    \item {\itshape\bfseries now in bold italic}
\end{itemize}
}
{\ttfamily This is the JetBrains Mono font:
\begin{itemize}
    \item {\itshape now in italic}
    \item {\bfseries now in bold}
    \item {\itshape\bfseries now in bold italic}
\end{itemize}
}
{\rmfamily This is the Brygada1918 font: 
\begin{itemize}
    \item {\itshape now in italic}
    \item {\bfseries now in bold}
    \item {\itshape\bfseries now in bold italic}
\end{itemize}
}
\end{document}