In case someone else is as simple as me, here is how you quote another post:
- Place your cursor at the position in your post where you want to insert a quote
- Go to the post you want to quote from
- Select the text you want to quote
- Three options will automatically appear above the selected text:
- Click “Quote” and the selected text will be inserted as a quote at the position of the cursor in your post
I spent ages looking for buttons and help on how to quote… 
I hope this saves others a bit of time.