solana-keygen new --outfile ~/my-kurac.json
After this command being executed and after BIP39 passphrase I receive pub key, which is not working on mainnet,testnet,devnet How do I fix this issue, + it's asking me to deposit to an account money to do Solana airdrop while if I can understand if it's on Devnet it has no value so it shouldn't ask me that
On Devnet the SOL has no value, but the rules are the same: you need SOL to perform transactions. The difference is that you can get it for free :)
If you have the CLI then you can just run solana airdrop 1 and that should give you 1 SOL.
If you have an issue with that, try using https://faucet.solana.com/
Keypair != Account
Keypair is just a two string which are being generated by some cryptographic algorithm, you need neither blockchain nor JSON RPC to generate keypair. You can do it on paper.
After generating them, you need to create an account in the blockchain. On Mainnet some other account should help you to create an account, somebody needs to be a signer. Nevertheless, on Devnet when you airdrop sols, System Program (Built-in smart contract) is signer and implicitly creates an account for you. Therefore, all you need to do is to run solana airdrop <AMOUNT> <ADDRESS>
