Hi @pngprakash, welcome to the forums! 
Are you referring to the product URL on your site, or where to find the details of a product on your seller dashboard?
The Catalog API does not have a way to return the URL of the product on your site. However, if you’re looking for the URL of the item details on your dashboard, it can be found by appending the item ID to the end of the items library URL:
https://squareup.com/dashboard/items/library/{Item ID}