deepl-translate.el

(require 'url-util)
(defun my:deepl-translate (&optional string)
  (interactive)
  (setq string
        (cond ((stringp string) string)
              ((use-region-p)
               (buffer-substring (region-beginning) (region-end)))
              (t
               (save-excursion
                 (let (s)
                   (forward-char 1)
                   (backward-sentence)
                   (setq s (point))
                   (forward-sentence)
                   (buffer-substring s (point)))))))
  (run-at-time 0.1 nil 'deactivate-mark)
  (browse-url
   (concat
    "https://www.deepl.com/translator#en/ja/"
    (url-hexify-string string)
    )))

(global-set-key (kbd "C-c C-c") 'my:deepl-translate)