Hi,

You can update the command for ConTeXt as follows:

Graphically:

M-x customize-variable *↵*

TeX-command-list *↵*

find the appropriate section for ConTeXt commands and change it with 
(e.g.) "context --purgeall %t" (see attached image).

Apply and save.

-----------------------------

Using the init.el you can also create your own commands:


(custom-set-variables
    '(ConTeXt-Mark-version "lmtx")
    '(ConTeXt-engine "lmtx"))


(eval-after-load "context"
   '(setq TeX-command-list
     (append
       '(
         ("context"
"context --purgeall %t"
           TeX-run-command t :help "Run context (lmtx)")
         ("luametatex"
"context --purgeall %t"
           TeX-run-command t :help "Run context (lmtx)")
       ) TeX-command-list
     )
   )
   )

I hope this helps.


Lizardo R.