HardhatError: HH101: Hardhat was set to use chain id 11155111, but connected to a chain with id 1.

[bobbywilliamajor]

require("@nomicfoundation/hardhat-toolbox")
require("dotenv").config()

/** @type import('hardhat/config').HardhatUserConfig */
const SEPOLIA_RPC_URL = process.env.SEPOLIA_RPC_URL
const PRIVATE_KEY = process.env.PRIVATE_KEY
module.exports = {
    defaultNetwork: "hardhat",
    networks: {
        hardhat: {},
        sepolia: {
            url: SEPOLIA_RPC_URL,
            accounts: [PRIVATE_KEY],
            chainId: 11155111,
        },
    },
    solidity: "0.8.8",
}

This code keeps returning to the following error:

HardhatError: HH101: Hardhat was set to use chain id 11155111, but connected to a chain with id 1.
    at ChainIdValidatorProvider.request

The code used to work. It's morethan 18 hours since l started working on it.

[zafi5]

check your .env file SEPOLIA_RPC_URL check url address