Hi,
Please install these two attached plugins, they will update the current mass action plugins and add an action which allow to update the canonical urls.
This language string can be added in the override part of the language file in Configuration > Languages:
HK_SET_CANONICAL="Set canonical url"
Then just set up a mass product action, and in the action select "Set canonical url" and fill the field with the desired url.
Something like:
https://domain.com/webshop/producten/product/{product_id}-{product_alias}
In this case the product_id and product_alias will automatically be replaced by the product information.