• Version: GNU Emacs 28.2

apt install eglot elpa-eglot clangd bear

(require 'eglot)
(add-to-list 'eglot-server-programs '((c++-mode c-mode) "clangd"))
(add-hook 'c-mode-hook 'eglot-ensure)
(add-hook 'c++-mode-hook 'eglot-ensure)

• M-, : xref-find-definitions