Urls or web addresses to Ebay product listings is incredibly long to the point of ridiculous. Attempting to manually type out and share a default, long ebay url on a cell phone would take about a week.
Fortunately, to shorten an Ebay.com url does not require a url shortener and the reason why is the most of the text that makes up that very long Ebay url has nothing to do with the actual web address to the Ebay list. Most of that very long Ebay url is tracking information for the owners of Ebay that tells Ebay things like how you got to the current Ebay page, what page you just came from on Ebay to get to the current page, etc.
Oddly, the web programmers at Ebay can make a small simple change to their web page coding to hide all that ugliness and to do so would not be very difficult on Ebay's part.
https://www.ebay.com/itm/
following by a string of numbers.?
that comes after the number.