Without seeing a working example it is difficult to help.

For articles, you'll have to use section-commands.

For reports and books, however chapter-commands are preferred.

Article classes

documentclass{article}
usepackage[page,toc]{appendix}


begin{document}
tableofcontents
section{First Section}
subsection{First Subsection}
section{Second Section}

begin{appendices}
section{Some Appendix}
Here be the appendix
end{appendices}

end{document}

Report or Book classes

documentclass{report}
usepackage[page,toc]{appendix}


begin{document}
tableofcontents
chapter{First Chapter}
section{First Section}
chapter{Second Chapter}

begin{appendices}
chapter{Some Appendix}
Here be the appendix
end{appendices}

end{document}