The Early Years Pupil Premium (EYPP) is additional DfE funding for early years settings in England and Wales, to improve the education they provide for 3- and 4-year-olds who are eligible for free school meals (or equivalent). Early years providers are any organisation offering education for children aged under 5, including nurseries and childminders.
There is guidance on the DfE website but you're likely to find more up-to-date guidance on your county council's website, which may well just require parents to provide you with their national insurance number, rather than filling out a form themselves. The amount per child attending their full 15 hours of funded education per week is 53p/hour or £302/year.
It is up to each EY provider how you spend the money - it can benefit all children in the setting but has to have a main focus on the needs of the EYPP children.