Came across a great website in my japanese learning studies a few weeks ago, Tofugu.
They do some pretty handy guides, one of which is about how to type in Hiragana or Katakana on a mac. You can see it here. Much easier than writing it into google transliterate and copy and pasting it into whatever document you’re working on!
The only down side is I keep forgetting I’ve left it in Hiragana, I tend to type without looking at what i’m writing so I’ve sent a few garbled tweets recently! I have to keep deleting them!