Open the URL and X will tell you the post is unavailable. That is the whole official answer. Bookmarks do not help: a bookmark is a pointer, so when the post goes, the bookmark goes blank. Likes and quote counts do not store the text for you either. If a post vanished from your bookmarks, why your Twitter bookmarks disappeared explains what happened.
Anything you can still read was copied somewhere else before the deletion. The methods below are those copies, in the order worth trying. None of them can reconstruct a post that nobody saved.