How to make keywords of my algorithm appear in bold?

Question

I want to write an algorithm in latex. But after compiling, it looks like that: As it looks, keywords like "Input", "Initialize","while", "end while" and "Output" don't appear in bold, I wonder if there is something wrong and how I can correct it.

    \begin{algorithm}
        \caption{Title of the Algorithm}
        \label{algo:ref}
        \begin{algorithmic}[1]
            \REQUIRE some words.  % this command shows "Input"
            \ENSURE ~\\           % this command shows "Initialized"
            some text goes here ... \\
            \WHILE {\emph{not converged}}
            \STATE ... \\  % line number at left side
            \ENDWHILE
            \RETURN this is the lat part.  % this command shows "Output"
        \end{algorithmic}
    \end{algorithm}

Besides, I used a template from Internet, and its introduction is as follows. Thanks for your help!

\documentclass[UTF8,a4paper,10pt]{ctexart}
\usepackage[left=2.50cm, right=2.50cm, top=2.50cm, bottom=2.50cm]{geometry} %页边距
\CTEXsetup[format={\Large\bfseries}]{section} %设置章标题居左
 
 
\setmainfont{STSong}   % 宋体
 
 \usepackage{authblk}
\usepackage{amsmath, amsfonts, amssymb} % math equations, symbols
\usepackage[english]{babel}
\usepackage{color}      % color content
\usepackage{graphicx}   % import figures
\usepackage{url}        % hyperlinks
\usepackage{bm}         % bold type for equations
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{epstopdf}
\usepackage{epsfig}
\usepackage{algorithm}
\usepackage{algorithmic}
\renewcommand{\algorithmicrequire}{ \textbf{Input:}}     % use Input in the format of Algorithm  
\renewcommand{\algorithmicensure}{ \textbf{Initialize:}} % use Initialize in the format of Algorithm  
\renewcommand{\algorithmicreturn}{ \textbf{Output:}}     % use Output in the format of Algorithm  
 \renewcommand{\theequation}{\arabic{section}.\arabic{equation}}
 
\usepackage{fancyhdr} %设置页眉、页脚
\lhead{}
\chead{}
\lfoot{}
\cfoot{}
\rfoot{}
 
 
\usepackage{hyperref} %bookmarks
\hypersetup{colorlinks, bookmarks, unicode} %unicode
 
 \makeatletter
\@addtoreset{equation}{section}
\makeatother
 
\title{\textbf{均匀设计方法综述}}
\author{ 陈海硕}
\affil{ 统计学院 }
\date{\today}

Answer 1

On the macOS 10.15, the warning says that the font TU/STSong(0)/b/n (font STSong bold) was unavailable (it doesn't exist) and that instead LaTeX used font TU/STSong(0)/m/n (font STSong).

Basically, you can't have bold (also italic) text with this set of fonts because this particular font doesn't exist.

Just delete the line \setmainfont{STSong} should resolve the issue or use another font that has both bold and italic shapes, e.g., Times New Roman.