从页眉中删除单词 Kapitel（章节）

Question

我想Kapitel从页眉中删除单词（章节）。我只想显示章节编号和名称。

主文本

\documentclass[12pt]{report}
\usepackage[a4paper, left={2.5cm}, right={2cm}, top={3cm}, bottom={3cm}, headheight=15pt]{geometry}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{blindtext}
\usepackage{titlesec}


\titleformat{\chapter}
  {\normalfont\LARGE\bfseries}{\thechapter}{1em}{}
\titlespacing*{\chapter}{0pt}{-10pt}{40pt}

\input{vorlage.tex}

\usepackage{fancyhdr}
\usepackage{lipsum}% just to generate text for the example


\fancypagestyle{plain}{%
  \fancyhf{}%
  \fancyhead[L]{\nouppercase{\leftmark}}%
  \fancyfoot[R]{\thepage}}
\pagestyle{plain}


\begin{document}

%% TITLESEITE %%
 \Title
      {Test1}   
      {Test2}   
      {xy}                           
      {zz}                            
      {zz}                               
      {test}                       
      {test}                      
      {17. Oktober 2021}     
\clearpage
%% INHALT %% 

\pagenumbering{roman}
\chapter*{\abstractname}
\addcontentsline{toc}{chapter}{\abstractname}
\markboth{\abstractname}{}
\newpage
\tableofcontents
\clearpage
%% TEXT %%
\pagenumbering{arabic}
\blinddocument

\blinddocument

\end{document}

文件名.txt

\newcommand{\Title}[8]{


\begin{titlepage}
    
    
        \normalfont \normalsize 
        \newcommand{\HRule}{\rule{\linewidth}{0.5mm}}
        
        \center
        \includegraphics[width=2.5in]{img/hft.png} \\[4ex]
        {\LARGE \textsc{Title}} \\[4ex]
        {\Large #1 #2}\\
           \vspace*{8ex}
        \HRule \\[0.4cm]
        { \huge \bfseries #3}\\[0.4cm] 
        \HRule \\[1.5cm]
          \vspace*{8ex}
        {\Large #4\\
                #5\\}

    \vspace*{16ex}
    \begin{flushleft}
        {\large
        Betreuung: \\
        #6 \\
        #7 \\
        \vspace*{4ex}
        #8 \\}
    \end{flushleft} 
        
        
    
        
    \end{titlepage}


}

我拥有的

我想要的是

我从@PietervanOostrum 那里得到了什么

\fancypagestyle{plain}{%
  \fancyhf{}%
  \fancyhead[L]{\nouppercase{\leftmark}}%
  \fancyfoot[R]{\thepage}}
\pagestyle{plain}
\renewcommand{\chaptermark}[1]{\markboth{\thechapter. #1}}