Some useful links: (1) https://docs.ethers.org/v5/api/providers/provider/ (2) https://codedamn.com/news/blockchain/introduction-to-ethers-js-complete-guide-2022 (3) https://docs.chain.link/resources/link-token-contracts (4) https://ethereum.org/developers/docs/standards/tokens/erc-20 (5) https://app.infura.io/