First edits made like in the video.

packages/contracts/src/addresses.js

@@ -1,5 +1,86 @@
-// This address points to a dummy ERC-20 contract. Replace it with your own smart contracts.
-const addresses = {
-  ceaErc20: "0xa6dF0C88916f3e2831A329CE46566dDfBe9E74b7",
+/**
+ * See all ids below
+ * https://ethereum.stackexchange.com/questions/17051/how-to-select-a-network-id-or-is-there-a-list-of-network-ids
+ */
+export const GOERLI_ID = 5;
+export const KOVAN_ID = 42;
+export const MAINNET_ID = 1;
+export const RINKEBY_ID = 4;
+export const ROPSTEN_ID = 3;
+
+const commonContracts = {
+  factory: "0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f",
+  router01: "0xf164fC0Ec4E93095b804a4795bBe1e041497b92a",
+  router02: "0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D",
+};
+
+export default {
+  [GOERLI_ID]: {
+    pairs: {
+      "DAI-WETH": "0x8F609d85ebC64316B0B2f9E53c11b4e48B7A06d2",
+    },
+    tokens: {
+      DAI: "0x697Ed3E98aaeCFa3121F536251F9D500de159dBa",
+      WETH: "0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6",
+    },
+    ...commonContracts,
+  },
+  [KOVAN_ID]: {
+    pairs: {
+      "DAI-WETH": "0xB10cf58E08b94480fCb81d341A63295eBb2062C2",
+    },
+    tokens: {
+      DAI: "0x4F96Fe3b7A6Cf9725f59d353F723c1bDb64CA6Aa",
+      WETH: "0xd0A1E359811322d97991E03f863a0C30C2cF029C",
+    },
+    ...commonContracts,
+  },
+  [MAINNET_ID]: {
+    pairs: {
+      "BAT-WETH": "0xB6909B960DbbE7392D405429eB2b3649752b4838",
+      "COMP-WETH": "0xCFfDdeD873554F362Ac02f8Fb1f02E5ada10516f",
+      "DAI-WETH": "0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11",
+      "LEND-WETH": "0xaB3F9bF1D81ddb224a2014e98B238638824bCf20",
+      "LINK-WETH": "0xa2107fa5b38d9bbd2c461d6edf11b11a50f6b974",
+      "MKR-WETH": "0xC2aDdA861F89bBB333c90c492cB837741916A225",
+      "USDC-WETH": "0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc",
+      "USDC-USDT": "0x3041CbD36888bECc7bbCBc0045E3B1f144466f5f",
+      "WBTC-WETH": "0xBb2b8038a1640196FbE3e38816F3e67Cba72D940",
+      "WETH-AMPL": "0xc5be99A02C6857f9Eac67BbCE58DF5572498F40c",
+    },
+    tokens: {
+      AMPL: "0xD46bA6D942050d489DBd938a2C909A5d5039A161",
+      BAT: "0x0D8775F648430679A709E98d2b0Cb6250d2887EF",
+      COMP: "0xc00e94Cb662C3520282E6f5717214004A7f26888",
+      DAI: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+      LEND: "0x80fB784B7eD66730e8b1DBd9820aFD29931aab03",
+      LINK: "0x514910771AF9Ca656af840dff83E8264EcF986CA",
+      MKR: "0x9f8F72aA9304c8B593d555F12eF6589cC3A579A2",
+      USDC: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
+      USDT: "0xdAC17F958D2ee523a2206206994597C13D831ec7",
+      wBTC: "0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599",
+      WETH: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
+    },
+    ...commonContracts,
+  },
+  [RINKEBY_ID]: {
+    pairs: {
+      "DAI-WETH": "0x8B22F85d0c844Cf793690F6D9DFE9F11Ddb35449",
+    },
+    tokens: {
+      DAI: "0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735",
+      WETH: "0xc778417E063141139Fce010982780140Aa0cD5Ab",
+    },
+    ...commonContracts,
+  },
+  [ROPSTEN_ID]: {
+    pairs: {
+      "DAI-WETH": "0x1c5DEe94a34D795f9EEeF830B68B80e44868d316",
+    },
+    tokens: {
+      DAI: "0xaD6D458402F60fD3Bd25163575031ACDce07538D",
+      WETH: "0xc778417E063141139Fce010982780140Aa0cD5Ab",
+    },
+    ...commonContracts,
+  },
 };
-export default addresses;