

On US English keyboards, there isn’t a universal, standard way to do it at the keyboard level.
I use Linux, and bind my Menu key on my keyboard to Compose. With Compose, I can tap “Compose-backtick-e” and get “è”.
Emacs has its own input methods, as do other environments.

















If you’re coding, your code editor may have some way to input that.
Some people who frequently input something like that use a snippet system.
In emacs, hitting most keys (like “*”) runs
self-insert-command. That takes a numeric parameter, so one can just do something like/ M-5 M-6 * /(slash, hold Alt, type 56, hit asterisk, slash) to get a slash followed by 56 asterisks followed by a slash.I’m not really a serious vim person, but I’m sure that vim has similar functionality.
searches
https://stackoverflow.com/questions/5054128/repeating-characters-in-vim-insert-mode
Looks like, in insert mode,
/ Control-o 56 a * Esc a /. Probably not using correct vim terminology for the keystrokes, but you get my drift.