Unfortunately your question is not very detailed, e.g.,
- how you want the bibliography shown,
- which class you are using.
However, it seems you don't want the result of \bibliographystyle{apa}. So maybe you want something like an author-year style. If so, you could, e.g., use package biblatex with option style=authoryear:
\documentclass{article}
\usepackage{csquotes}
\usepackage[style=authoryear]{biblatex}
\addbibresource{biblatex-examples.bib}% This is only an example, provided by
% biblatex and therefore useful for minimal
% working examples.
\nocite{*}% Show all references from the database.
\begin{document}
\printbibliography[title=Bibliography]
\end{document}
After running LaTeX + Biber + LaTeX + LaTeX (LaTeX can be either PDFLaTeX, LuaLaTeX or XeLaTeX), you would get a document with six pages of bibliography. The first one:

You can get something similar using BiBTeX with \bibliographystyle and \bibliography, but with less flexibility:
% Following environment is just used to generate an example bib-file.
% Ususally you would not use it in a real document.
\begin{filecontents}[overwrite]{\jobname.bib}
@book{Agrawa2021,
author={Agrawal, G.},
year=2021,
title={Fiber-Optic Communication Systems},
publisher={Wiley}
}
\end{filecontents}
\documentclass{article}
\usepackage[english]{babel}
\addto\captionsenglish{\def\refname{Bibliography}}
\usepackage{natbib}
\bibliographystyle{apalike}
\begin{document}
\nocite{*}
\section{One test section}
\bibliography{\jobname}
\end{document}
In this case you have to run LaTeX + BibTeX + LaTeX + LaTeX to get:

Note: There are already a lot of questions about making bibliographies using either BibTeX and some packages like natbib or apastyle, or using biblatex and biber. For information about setting up your editor to use biber instead of bibtex see, e.g., Biblatex with Biber: Configuring my editor to avoid undefined citations
If you have further questions about making a bibliography please ask a new more detailed question and also add a minimal working example with bibliography.
biblatexwith optionstyle=authoryearto have a bibliography without such kind of labels. The default title depends on the used class. For examplearticleusesReferences, butreportandbookuseBibliography. You can change this indeed redefining\refnameresp.\bibname.biblatexalso provides an option. – cabohah Jun 23 '23 at 09:33