Описание изменений

backend/hardhat.config.cjs

@@ -0,0 +1,12 @@
+require("@nomiclabs/hardhat-waffle");
+require("dotenv").config();
+
+module.exports = {
+  solidity: "0.8.0",
+  networks: {
+    sepolia: {
+      url: process.env.ETHEREUM_NETWORK_URL,
+      accounts: [process.env.PRIVATE_KEY]
+    }
+  }
+};