There's actually two ways:

The first way is very easy, On the right of a deviation there's a share section. What you do is click on the arrow pointing down, and copy and paste the text in the thumb box to a journal, ect.

The other way is still easy. On the address bar. you can see a series of numbers at the very end of the link. What you do is: Copy those numbers and then type it just like this on a journal: :thumb167025792:

I hope I explained it enough. xD