This is my emacs setup for AUCTEX with ConTeXt.

;; Install straight.el
(defvar bootstrap-version)
(let ((bootstrap-file
       (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
      (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
        (url-retrieve-synchronously
         "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
         'silent 'inhibit-cookies)
      (goto-char (point-max))
      (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))



;; Install use-package
(straight-use-package 'use-package)


;; Configure use-package to use straight.el by default
(use-package straight
             :custom (straight-use-package-by-default t))




(use-package yasnippet)

;;; Auctex


(defun my-context-setup ()
  (custom-set-variables
   '(ConTeXt-Mark-version "LMTX")
   '(ConTeXt-engine "lutametatex")))

	

 (straight-use-package 'auctex)


(add-hook 'ConTeXt-mode-hook
	  (lambda ()
	    (reftex-mode 1)
            (flyspell-mode 1)
	    (auto-fill-mode 1)
	    ;(relative-line-numbers-mode 1)
	    ;(abbrev-mode 1)
	    (my-context-setup)
	    (yas-minor-mode)
	    (yas-reload-all)))


I hope this help you

Mauricio