This is fixed in the class definition file. However, you can change the format. The command that produces the titles is \@maketitle
. It contains the command \raggedright
two times, once for the title and once for the author information. Replacing each instance by \centering
produces the required result. This can be achieve by patching the command as follows
\usepackage{etoolbox}
\makeatletter
\patchcmd{\@maketitle}{\raggedright}{\centering}{}{}
\patchcmd{\@maketitle}{\raggedright}{\centering}{}{}
\makeatother

\documentclass[fleqn,11pt]{wlscirep}
\usepackage{authblk}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{fourier}
\usepackage{array}
\usepackage{makecell}
\usepackage{lipsum}
\usepackage{etoolbox}
\makeatletter
\patchcmd{\@maketitle}{\raggedright}{\centering}{}{}
\patchcmd{\@maketitle}{\raggedright}{\centering}{}{}
\makeatother
\begin{document}
\title{cccccc}
\author{xxxx}
\affil{vvvvv}
\affil{vvvvv}
\begin{abstract}
x
\end{abstract}
\maketitle
\end{document}