Previously, people have said canned tomatoes have added salt in the US [2], which they don't tend to have in Europe [3] (choosing the basic, cheap brand in both cases).
[1] https://www.walmart.com/browse/food/frozen-vegetables/976759...
[2] https://www.walmart.com/ip/Great-Value-Petite-Diced-Tomatoes...
[3] https://www.tesco.com/groceries/en-GB/products/299768716