Rename "Appendices" in the table of contents and in the text

Rename "Appendices" in the table of contents and in the text

I would like to change the name of the Appendices to"Appendix" in the
table of contents. So far, I was only able to change the name of the
Appendices in the text, by using the following commands in the preamble:
\renewcommand\appendixname{Appendix}
\renewcommand\appendixpagename{Appendix}
Also, I was able to add "Appendix" to the Table of Contents by using the
command:
\addcontentsline{toc}{chapter}{Appendix}
However, using this I have both the default "Appendices" and the added
"Appendix" in the table of contents. Does anyone know how to remove or
rename "Appendices" in the Table of Contents?
Thx!