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you can share your btc adress but dont share your private key because people need your btc adress to send bitcoins to you and again dont share your private key its the only proof that you own that bitcoin

how do I find the private key? if it's being held on an exchange

Exchanges dont give you your private key (atleast i didnt saw one exchange give your private key ) if u want get your private key you can use paper wallet or offline wallet

or could that just mean password

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