I am using springer nature \documentclass[sn-mathphys]{sn-jnl}, and I need citations like (Nielsen and Chuang 2010) but it is coming like [1]

Question

I am using springer nature

\documentclass[sn-mathphys]{sn-jnl}, 

and I need citations like (Baireuther 2018) but it is coming like 1. I have used \usepackage{natbib}. Followed by:

\begin{document}
\bibliographystyle{plainnat}

I dont know where I am getting wrong. By sample tex file input:

@article{baireuther2018machine,
  title={Machine-learning-assisted correction of 
         correlated qubit errors in a topological code},
  author={Baireuther, P and others},
  journal={Quantum},
  volume={2},
  pages={48},
  year={2018},
  publisher={Verein zur F{\"o}rderung des Open Access 
             Publizierens in den Quantenwissenschaften}
}

sample:

\documentclass[sn-mathphys]{sn-jnl}
\usepackage{natbib}
\usepackage{enumerate}
\usepackage{lmodern}
\begin{document}
\bibliographystyle{plainnat}
\title{ aaa bbb ccc}
\author*[1]{\fnm{xxx} \sur{ yyy}}
\maketitle
\section{Introduction}\label{sec1}
aaaaa \cite{baireuther2018machine}
\bibliography{sn-bibliography}
\end{document}

Coming as

Answer 1

Using \documentclass[sn-mathphys]{sn-jnl} already defines a bibliography style namely \bibliographystyle{sn-mathphys}. Therefore writing \bibliographystyle{plainnat} tries to redefine the bibliography style and causes an error. One possible solution is to just write \documentclass{sn-jnl} without "sn-mathphys" or you may edit the definitions in sn-jnl.cls itself.