I don't think you can at the moment, but Luxardo's UK distributor changes this month (July 2025), so hopefully they will add this product to their range in the near future.

Previously, the brands you placed in Your Ingredients would automatically be shown in cocktail recipes. This caused much confusion so now our default brand or generic ingredient will display in your recipes unless you change the brand displayed using our new preferred brand function. With Premium membership, you can set a preferred brand across a generic category (e.g. Ketel One for vodka) &/or set preferred brands for individual recipes (e.g. a different brand of vermouth in your Negroni than your Manhattan). I’ll add notes on how to do this on the “Preferred brands” page accessible from your Premium dashboard; in the meantime please see:
https://www.diffordsguide.com/g/1097/diffords-guide/faqs