Searching it up I'm not finding anything (there are a lot of poorly documented Maltese foods online). But it's one of those ones that most Maltese pizza places have (not the ones doing specifically neopolitan style, but doing more local stuff). It varies from place to place but always topped with stereotypically Maltese things. Potatoes and Maltese sausage are v common, but you also find olives and dried peppered ġbejniet on em (can be replaced by any quick dried goats or sheep's cheese and some pepper), some places add boiled eggs too, but that's probably the most devicive topping (I hate it personally). If you wanna try making it at home, look up how people in Rome do potatoes on pizza, and you can make your own Maltese sausage mix easily. Traditionally Maltese sausages are made in autumn when we get a particularly dry wind, heavily salted and then left to dry in that wind. You get a particularly taste from that, so most people don't bother making em and buy them from the local butchers instead. If you're making em at home I recommend leaving the mix to sit over night in the fridge so it all gets to know it's self. For pizza or pasta you really don't need to worry about stuffing it into a casing, you usually pop it out anyways.

This recipe looks about right to me for the sausage: https://www.tal-forn.com/2013/06/zalzett-malti-maltese-sausage-2/

We use Maltese sausage on pizzas, in pastas, tomatoey stews etc. Any where that it can lend it's strong taste out or lend the salt etc. We also like, always include em when we're doing BBQs, but they're so salty you really can't have more then 1 in that context lol.