The hook is begindocument/before

instructions.tex

@@ -46,7 +46,7 @@ If you are writing a PhD dissertation, you will want to edit \path{main-disserta
 \item [Overleaf Template:]  \url{https://www.overleaf.com/latex/templates/reykjavik-university-project-report-and-thesis-template/fcwvcgnstrjs}
 \item [Actively developed code:] \url{https://gitea.cs.ru.is/foley/ru-thesis}
 \item [Current maintainer:] Joseph Timothy Foley.
-  His email is his last name AT \textt{ru.is}
+  His email is his last name AT \texttt{ru.is}
 \end{description}
 
 \section{Frequently Asked Questions}
@@ -273,7 +273,7 @@ TexMaker and TeXStudio require a configuration change to do this.
   OSX sometimes cares.
   Linux always cares.
 \item \LaTeX{} generates a bunch of temporary files that you don't want to put into version control.
-  Look at Appendix~\label{src:gitignore-example} for a list of extensions.
+  Look at Appendix~\ref{src:gitignore-example} for a list of extensions.
 \end{itemize}
 
 \section{Department of Engineering Information}

ruthesis.sty

@@ -336,7 +336,7 @@ in this publication does not imply, even in the absence of a specific statement
 
 
 %%%%%%%%%% Metadata for pdf file %%%%%%%%%%%%%%%%%%%%%%
-\AddToHook{beforedocument/before}{%
+\AddToHook{begindocument/before}{%
   %% package hyperref needs to be last, so we use a hook
   \PassOptionsToPackage{hidelinks}{hyperref}%disable boxes around links
   \RequirePackage{hyperref}