Currently the umalayathesis class uses apacite to implement the bibliography style, but apacite supports only APA6. For full APA7 it would be necessary to use biblatex-apa; no BibTeX style for full APA7 exists yet.

I’m still hoping (against hope?) that one day, the apacite package will be updated to support APA7, so that umalayathesis.cls won’t need to undergo overhauling…

But for now, if you want to use full APA7, it may actually be easier to make the following changes within thesis.tex itself.

Add these lines before \documentclass:

\RequirePackage{scrlfile}
\PreventPackageFromLoading{multibib}
\providecommand{\newcites}[2]{}

Make sure to add the custombib option in the \documentclass declaration:

\documentclass[english,singlespacedlisttitles,custombib]{umalayathesis}

And then add these lines after \documentclass:

\usepackage[natbib,style=apa]{biblatex}
\addbibresource{myrefs.bib}
\setlength\bibitemsep{2\onelineskip}
\setlength\bibhang{0.5in}
\renewcommand{\bibfont}{\SingleSpacing}

Next remove or comment out these lines:

\bibliography{myrefs}
\nociteown{Lim:2009,Bond:etal:WordNetBahasa:2014}
\bibliographyown{myrefs}

Add instead:

\cftinserthook{toc}{PlainChapTocLines}
\cftinserthook{toc}{disableuppercase}
\printbibliography[heading=bibintoc,title=\refname]
 
\begin{refsection}
\nocite{Lim:2009,Bond:etal:WordNetBahasa:2014}
\printbibliography[heading=bibintoc,title=\listpubname]
\end{refsection}

If you are using the splitpubs environment to separate your publication list for journal articles and conference proceedings, then change your splitpubs in your .tex file to be:

\begin{splitpubs}
\begin{refsection}
\nocite{Bond:etal:WordNetBahasa:2014}
\printbibliography[heading=subbibintoc,title={List of Publications:}]
\end{refsection}
 
\begin{refsection}
\nocite{Lim:2009}
\printbibliography[heading=subbibintoc,title={Papers Presented:}]
\end{refsection}
\end{splitpubs}

After making these changes, delete the previously generated .bbl files (if any) in the directory.

Then run pdflatex, biber, pdflatex, pdflatex. Note that the biber processor must be used instead of bibtex now.

(If compiling on Overleaf, it should all “just work” because the build tool knows which processor to use.)