From the following answer: https://tex.stackexchange.com/a/270484/201720,
one can refer to an appendix by letter, which is what I want to achieve. However, I do not want the output to be:

Instead, I want the following:
- I want to add a section number before "Appendices"
- Instead of "A Graph Appendix", I want "Appendix A: Graph Appendix
In other words, I want the output to be like this (in my case, appendices will be section 9):

Is there a way to do this?
I could write (from https://tex.stackexchange.com/a/30123/201720):
\section{Appendices}
\subsection*{Appendix A: Graph Appendix} \label{appendix:a}
\addcontentsline{toc}{subsection}{\protect\numberline{}Appendix A: Graph Appendix}
This is the graph appendix. It is appendix \ref{appendix:a}.
Because I do not want the subsection to be numbered. But when I do this, latex references section 9 (because of the asterisk*, I think), so I get this:

But even if I remove the asterisk, latex will reference section 9.1. i.e. I will get this:

