Latex 添加关键字keywords

无论是自己写的模板还是下载的模板没有keywords

\newcommand\keywords[1]{\textbf{Keywords}: #1}

\keywords{keywords1， keywords2， keywords3.}

加上全文模板

\documentclass[11pt,a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{authblk}
%关键字环境
\newcommand\keywords[1]{\textbf{Keywords}: #1}

\title{More than one Author with different Affiliations}
\author[a]{Author A}
\author[a]{Author B}
\author[a]{Author C \thanks{Corresponding author: email@mail.com}}
\author[b]{Author D}
\author[b]{Author E}
\affil[a]{Department of Computer Science, \LaTeX\ University}
\affil[b]{Department of Mechanical Engineering, \LaTeX\ University}

% 使用 \thanks 定义通讯作者
\renewcommand*{\Affilfont}{\small\it} % 修改机构名称的字体与大小
\renewcommand\Authands{ and } % 去掉 and 前的逗号
\date{} % 去掉日期

\begin{document}
 \maketitle
\begin{abstract}
    **********
\end{abstract}
%关键字
\keywords{keywords1， keywords2， keywords3.}
\end{document}