[NTG-context] The appendices envrionment and title in toc

I want to include appendices part in MKIV. The appendices should prefixed by Appendix, like Appendix A, Appendix B. I use \setuplabeltext [appendix=Appendix ] \startappendices \component chapters/appen-01 \stopappendices appen-01.tex is the appendix file. The appendix part tile is correct, but in the toc, the title is something like Chapter A. How to solve this problem?