Web3.js Uniswap Issue – Transaction Reverted During `swapExactTokensForTokens` on UniswapV2Router02

I am attempting to swap ETH for DAI using the Uniswap Router, but am facing a problem where the transaction gets reverted, along with the following message: Transaction has been reverted by the EVM.

I am testing this on the Rinkeby Testnet.

Here is the full message, along with the accompanying block information:

Transaction has been reverted by the EVM:
    {
      "blockHash": "0xfaa3effa60d646ef4db959cba460dac74aafd1c0b667c91758be71a735f949ce",
      "blockNumber": 9146763,
      "contractAddress": null,
      "cumulativeGasUsed": 1678679,
      "effectiveGasPrice": "0x3b9aca09",
      "from": "0xbd8b57fdbd794f125a9d6a3a7bd8958d46201b37",       
      "gasUsed": 30348,
      "logs": [],
      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "status": false,
      "to": "0x7a250d5630b4cf539739df2c5dacb4c659f2488d",
      "transactionHash": "0x7c5b33a7a751430ba0e0347a29b01a12db0b1da71a17a36deb4c773ea5ff483c",
      "transactionIndex": 6,
      "type": "0x0"
    }

      at Object.TransactionError (../node_modules/web3-core-helpers/lib/errors.js:87:21)
      at Object.TransactionRevertedWithoutReasonError (../node_modules/web3-core-helpers/lib/errors.js:98:21)
      at ../node_modules/web3-core-method/lib/index.js:394:57

I will also provide the NodeJS code I am running:

import Web3 from "web3";

const IERC20 = require('@uniswap/v2-periphery/build/IERC20.json')
const IPair = require('@uniswap/v2-core/build/IUniswapV2Pair.json')  
const IFactory = require('@uniswap/v2-core/build/IUniswapV2Factory.json')
const IRouter = require('@uniswap/v2-periphery/build/IUniswapV2Router02.json')

export class TransactionService {

async transact() {
    const privKey = "<privkey ommitted>";
    var web3 = new Web3('https://rinkeby.infura.io/v3/<infura-rinkeby-path>');
    var factory = new this.web3.eth.Contract(IFactory.abi, "0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f");
    var address = "0xbd8B57fdBD794f125a9D6A3A7bd8958D46201b37";
    var daiExchangeAddress = "0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735";
    var ethExchangeAddress = '0xc778417E063141139Fce010982780140Aa0cD5Ab';
    var rinkebyRouterAddress = '0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D';
    var router = new this.web3.eth.Contract(IRouter.abi, rinkebyRouterAddress);
    var token0 = new this.web3.eth.Contract(IERC20.abi, ethExchangeAddress) //henceforth T0
    var token1 = new this.web3.eth.Contract(IERC20.abi, daiExchangeAddress) //and T1    
    var pair = new this.web3.eth.Contract(IPair.abi,
      (await factory.methods.getPair(token0.options.address, token1.options.address).call()));
    
      const gasPrice = await web3.eth.getGasPrice()
      const gasNeeded = (0.15*10**6)*2 
      const path = [token0.options.address,token1.options.address]
      var amountIn = 999999999999;
      var tx0 = {
        to: token0.options.address, 
        gas: gasNeeded, 
        data: token0.methods.approve(router.options.address,amountIn).encodeABI()
    }

    var signedTx0 = await web3.eth.accounts.signTransaction(tx0, privKey);
    var receipt0 = await web3.eth.sendSignedTransaction(signedTx0.rawTransaction)
    
    console.log(
        `Tx mined\n`+
        `Tx hash: ${receipt0.transactionHash}\n`
        )
    const tx1 = {
        to: router.options.address, 
        gas: gasNeeded,
        data: router.methods.swapExactTokensForTokens(
            amountIn,
            0,
            path,
            address,
            (Date.now() + 250)
        ).encodeABI()
    }

    var signedTx1 = await web3.eth.accounts.signTransaction(tx1, privKey);
    var receipt1 = await web3.eth.sendSignedTransaction(signedTx1.rawTransaction);
}

}

As you can see, there are two transactions made. Anapprove and a swapExactTokensForTokens. The contract ABI can be found here. Some documentation on the Router02 is here. The contract itself can be found here. Thank you for any help you can provide.