Not very clear what you are trying to do but if you want to import your Brave Wallet to MetaMask then you can go to brave://wallet/crypto/backup-wallet and copy the seed phrase and then import it in Metamask. Note it will only export the primary account with the seed and not imported ones via private key/JSON.
If you have an older 24 word seed phrase you’ll have to export your private key by clicking on the account then the pencil icon. Then importing that account to MetaMask.