texlab & lsp-latex & lsp-mode

It works! Thanks for the developers' efforts!

GitHub - ROCKTAKEY/lsp-latex: Emacs lsp-mode client for LaTeX, on texlab.

GitHub - latex-lsp/texlab: An implementation of the Language Server Protocol for LaTeX

GitHub - ROCKTAKEY/lsp-latex: Emacs lsp-mode client for LaTeX, on texlab.

(use-package lsp-latex
  :ensure t
  :config
  (with-eval-after-load "tex-mode"
    (add-hook 'tex-mode-hook 'lsp)
    (add-hook 'latex-mode-hook 'lsp))
  (with-eval-after-load "yatex"
    (add-hook 'yatex-mode-hook 'lsp))
  (with-eval-after-load "bibtex"
    (add-hook 'bibtex-mode-hook 'lsp))
)