I am writing to you about a problem with ConTeXt LMTX and TeXShop 5.11 on macOS 12.6.3 (MacBook Air M2).

Yesterday I installed LMTX on my computer following the instructions here:

https://wiki.contextgarden.net/Installing_ConTeXt_LMTX_on_MacOS

The LMTX tree is correctly installed in the directory I've chosen:

charlie@Air-di-Tommaso ~ % which luametatex
/Users/charlie/Documents/ConTeXt/ConTeXt-LMTX/tex/texmf-osx-arm64/bin/luametatex
charlie@Air-di-Tommaso ~ % type luametatex
luametatex is /Users/charlie/Documents/ConTeXt/ConTeXt-LMTX/tex/texmf-osx-arm64/bin/luametatex
charlie@Air-di-Tommaso ~ % luametatex --version
This is LuaMetaTeX, Version 2.10.06

Execute 'luametatex --credits' for credits and version details.

There is NO warranty. Redistribution of this software is covered by the terms
of the GNU General Public License, version 2 or (at your option) any later
version. For more information about these matters, see the file named COPYING
and the LuaMetaTeX source.

Functionality : level 20230126
Support : context@ntg.nl
Copyright : The Lua(Meta)TeX Team(s) (2005-2022+)

The LuaMetaTeX project is related to ConTeXt development. This macro package
tightly integrates TeX and MetaPost in close cooperation with Lua. Updates will
happen in sync with ConTeXt and when needed. Don't be fooled by unchanged dates:
long-term stability is the objective.

However, I also get this:

charlie@Air-di-Tommaso ~ % luametatex
startup error : no format file given, quitting

Also, I created the TeXShop engine as indicated on the page (I've done it before with no problems).
However, now when I run LMTX from editor to compose a source, the source is compiled with MkIV Standalone, which I have in another folder (/Users/charlie/Documents/ConTeXt/ConTeXt-MkIV). LMTX doesn't even work from a terminal, of course.

The curious thing is that even by launching the ConTeXt present in TeX Live, what really works is always MkIV Standalone.

Do you have any idea where I might have gone wrong?

Thank you very much

Tommaso