Is there a hotkey for paste in ubuntu emacs?

"S-Insert works for me.

<S-insert> runs the command yank, which is an interactive compiled
Lisp function in `simple.el'.

It is bound to <S-insert>, <S-insertchar>, C-y.

(yank &optional arg)

Reinsert (""paste"") the last stretch of killed text.
More precisely, reinsert the stretch of killed text most recently
killed OR yanked. Put point at end, and set mark at beginning.
With just C-u as argument, same but put point at beginning (and mark at end).
With argument N, reinsert the Nth most recently killed stretch of killed
text.

When this command inserts killed text into the buffer, it honors
`yank-excluded-properties' and `yank-handler' as described in the
doc string for `insert-for-yank-1', which see.

See also the command `yank-pop' (M-y)."