Easy to get in the U.K.
Plenty of places you can get hold, Liddle, Tesco, Sainsbury’s all the supermarkets should have it.
Make sure you get a decent one as they can sometimes taste a bit ‘medicine’ like and a bit harsh.
You can get cream versions a bit like Baileys but much nicer and obviously lemon flavour.
Italians do like a nice digestif and make some wonderful versions like Orancino which is the orange version (which I prefer) and things like pistachio, almond, chocolate versions of the liqueur.