On most keyboard (linux and windows) you can just type [Alt Gr] + [4] (which is also [$]).
Edit: only actually tested on English/British keyboard layouts, though I assume we've got legislation in place to remove this mapping when we leave the EU.
Edit: only actually tested on English/British keyboard layouts, though I assume we've got legislation in place to remove this mapping when we leave the EU.
Other people say it's alt-gr + e, so that'd be holding the alt-gr key and tapping E