This is just the standard Twitter page right? As far as I can tell, the "Copy link to Tweet" is the exact same URL as what you'll get when you hover over the date.
That element is much easier to select, and does indeed contain the URL. This simple scrape demonstrates:
{"_id":"twitter_get_urls","startUrl":["https://twitter.com/pampamLondon"],"selectors":[{"id":"tweet_selectors","type":"SelectorElement","parentSelectors":["_root"],"selector":"div.tweet","multiple":true,"delay":0},{"id":"get_date","type":"SelectorText","parentSelectors":["tweet_selectors"],"selector":"div.content > div.stream-item-header > small","multiple":false,"regex":"","delay":0},{"id":"url","type":"SelectorElementAttribute","parentSelectors":["tweet_selectors"],"selector":"div.content > div.stream-item-header > small > a","multiple":false,"extractAttribute":"href","delay":0}]}