diff --git a/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/README.md b/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/README.md
index 8b13789..cc08eee 100644
--- a/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/README.md	
+++ b/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/README.md	
@@ -1 +1,52 @@
+# Validate version of Testnet you've used to create Wallet.
+
+The code provided by the instructor generated a Wallet compatible with Testnet version 3. That leads to problems while verifying the creation of the wallet for some blockchain validators.
+
+I could validate my wallet using https://blockstream.info/testnet and get a faucet using https://coinfaucet.eu/en/btc-testnet/
+
+I've also researched how to generate the code to create wallets for Testnet version 4, as Testnet 3 should be "deprecated" soon, as shown below:
+
+'''
+        // Importing dependencies
+        const bip32 = require('bip32');
+        const bip39 = require('bip39');
+        const bitcoin = require('bitcoinjs-lib');
+
+        // Define network parameters for Testnet4
+        const testnet4 = {
+        messagePrefix: '\x18Bitcoin Signed Message:\n',
+        bech32: 'tb',
+        bip32: {
+            public: 0x043587cf,  // Base58 prefix for xpub on Testnet4
+            private: 0x04358394  // Base58 prefix for xprv on Testnet4
+          },
+          pubKeyHash: 0x6f,      // P2PKH starts with 'm' or 'n'
+          scriptHash: 0xc4,      // P2SH starts with '2'
+          wif: 0xef              // Wallet Import Format prefix
+        };
+
+        // HD wallets derivation path for Testnet4
+        const path = `m/49'/1'/0'/0`;
+
+        // Generating mnemonic (seed phrase)
+        let mnemonic = bip39.generateMnemonic();
+        const seed = bip39.mnemonicToSeedSync(mnemonic);
+
+        // Creating HD wallet root from the seed
+        let root = bip32.fromSeed(seed, testnet4);
+
+        // Deriving account and generating address
+        let account = root.derivePath(path);
+        let node = account.derive(0).derive(0);
+
+        let btcAddress = bitcoin.payments.p2pkh({
+          pubkey: node.publicKey,
+          network: testnet4,
+        }).address;
+
+        console.log("Generated Wallet for Testnet4");
+        console.log("Address: ", btcAddress);
+        console.log("Private Key: ", node.toWIF());
+        console.log("Seed Phrase: ", mnemonic);
+'''
 
diff --git a/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/src/createWallet-T4.js b/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/src/createWallet-T4.js
new file mode 100644
index 0000000..d77500a
--- /dev/null
+++ b/Modulo 01 Fundamentos da Blockchain/Curso 01 Introducao a Blockchain/Criando e utilizando a sua carteira de criptomoedas/src/createWallet-T4.js	
@@ -0,0 +1,42 @@
+// Importing dependencies
+const bip32 = require('bip32');
+const bip39 = require('bip39');
+const bitcoin = require('bitcoinjs-lib');
+
+// Define network parameters for Testnet4
+const testnet4 = {
+  messagePrefix: '\x18Bitcoin Signed Message:\n',
+  bech32: 'tb',
+  bip32: {
+    public: 0x043587cf,  // Base58 prefix for xpub on Testnet4
+    private: 0x04358394  // Base58 prefix for xprv on Testnet4
+  },
+  pubKeyHash: 0x6f,      // P2PKH starts with 'm' or 'n'
+  scriptHash: 0xc4,      // P2SH starts with '2'
+  wif: 0xef              // Wallet Import Format prefix
+};
+
+// HD wallets derivation path for Testnet4
+const path = `m/49'/1'/0'/0`;
+
+// Generating mnemonic (seed phrase)
+let mnemonic = bip39.generateMnemonic();
+const seed = bip39.mnemonicToSeedSync(mnemonic);
+
+// Creating HD wallet root from the seed
+let root = bip32.fromSeed(seed, testnet4);
+
+// Deriving account and generating address
+let account = root.derivePath(path);
+let node = account.derive(0).derive(0);
+
+let btcAddress = bitcoin.payments.p2pkh({
+  pubkey: node.publicKey,
+  network: testnet4,
+}).address;
+
+console.log("Generated Wallet for Testnet4");
+console.log("Address: ", btcAddress);
+console.log("Private Key: ", node.toWIF());
+console.log("Seed Phrase: ", mnemonic);
+