it's an API. you can access an API with nearly every language you like.
Exactly. It's really not about what language can interact with the API, It's which language you want to learn. However, I wouldn't exactly pick something like Java for this when compared to PHP. You would be able to learn PHP quicker (due to less of a learning curve) and have something out in production quicker with less setup time.
FaucetHub also has a PHP Library for interacting with their API, which may make your life a little easier. But if using a library, do your best to fundamentally understand how the library works instead of just using it and forgetting it.
https://faucethub.io/phplib