Use reftex-label to insert labels

The advantage is that it automatically adds the label to the
completion list.

global.org

@@ -904,6 +904,7 @@
       (add-hook 'LaTeX-mode-hook
             (lambda ()
           (turn-on-reftex)
+          (setq reftex-plug-into-AUCTeX t)
           (setq prettify-symbols-alist nil)
           (add-to-list 'prettify-symbols-alist '(" ⊂ " . (? (Br . Bl) ? (Br . Bl) ?)))
 
@@ -926,6 +927,7 @@
           (define-key LaTeX-mode-map (kbd "M-S-SPC") 'TeX-insert-braces)
 
           (define-key LaTeX-mode-map (kbd "C-c C-v") 'wilder/TeX-insert-reference)
+          (define-key LaTeX-mode-map (kbd "C-c C-l") 'reftex-label)
           (define-key LaTeX-mode-map (kbd "C-M-<return>") 'wilder/TeX-insert-align)
 
           ;; unbind return - NOTE it is important to unbind