When you create your wallet, nowadays usually hierrachial deterministic wallets (HD wallets), you have mnemonic seed with which you can have many private keys for different public addresses.
https://learnmeabitcoin.com/technical/keys/hd-wallets/

Depends on each wallet software, you will have different ways to export your Bitcoin private keys. Search export private key + your wallet software name, and I believe you can find answers.

Remember, it's your private key, it's your bitcoin so never share your Bitcoin private keys with anyone.