rich1.0hong (npub1jp…uqgsz)https://yabu.me/npub1jpvsahpy0vgq7gu8nfqjkeskce0gwjk8jpss590xkvjh5xxe4epsruqgsznjumphttps://yabu.metrying to understand the chainlink proof of reserves product for bitcoin etfs. for example this is the site for arkb (https://data.chain.link/feeds/ethereum/mainnet/arkb-por) how does this work? seems like it's not really tied to the bitcoin blockchain and is simply a custodian attestation but how do the chainlink oracles get access to arkb's bitcoin balance at coinbase? it's non public information no?