For usage Clone repo and see it cannot be run locally so you cannot do much by cloning Otherwise clone add entity and yarn codegen to generate typings and function for entity bucket then update mapping and build it using
graph codegen && graph build
# after this add you auth key using
graph auth --studio [Your key]
graph deploy --studio [graph name]
Both Repo NFT MARKET GRAPH API AND Its OPen API on Graph DOC: https://docs.google.com/document/d/1L5C7Ly7nvcoPwnWULtajUgpR1XLgRdGx4NAq2zKqqjw/edit?usp=sharing