Is it possible to spend a coinbase output?

[CharikovAI]

I'm trying to spend a generated UTXO in this way:

final keyPair = ECPair.fromWIF(wif, network: regtest);
 var p2pk = new P2PK(
                        data: new PaymentData(pubkey: keyPair.publicKey),
                        network: regtest)
                    .data;
final txb = new TransactionBuilder(network: regtest);
txb.setVersion(1);
txb.addInput(
                        input.id,
                        input.outputIndex,
                        null,
                        p2pk.output
                      );
// ..... addOutput and sign

After broadcasting I'm getting an error mandatory-script-verify-flag-failed (Signature is found in scriptCode) (code 16)
If it is possible can you provide an example how to do this ?