章，节，小节标题的字体更改

Question

因此，我正在努力更改乳胶中标题/部分/小节的字体。

这是我的代码：

% !TEX TS?program = pdflatexmk

\documentclass[fontsize=12pt]{book}

\usepackage[T1]{fontenc}

\usepackage{amsmath}

\usepackage{mathpazo}

%changing font of section/chapter title
\usepackage{fontspec}
\usepackage{titlesec}
\newfontfamily\headingfont{Papyrus}
\titleformat{\chapter}{\LARGE\headingfont}
\titleformat{\section}{\LARGE\headingfont}
\titleformat{\subsection}{\Large\headingfont}
\titleformat{\subsubsection}{\large\headingfont}



\title{my report}
\author{user name}
\date


\linespread{1.5}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\maketitle
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\tableofcontents
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\chapter{introduction}
text : intro
\section{first section}
text :  section
\subsection{this subsection}
text :section
\subsubsection{this and that subsection}
text :subsub
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\end{document}

这是输出： 字体仅在chapter和subsection中实现。不适合其他人。 而且编号也会丢失。例如，没有titlesec和fontspec就是这样。章和小节的编号随之丢失。 我找不到错误。 （使用fontspec也很烦人，因为它找不到默认的乳胶字体，因此不得不将otf文件复制粘贴到工作目录中）