Web3 app on Ethereum

Being intrigued by blockchain technology for some time now, I decided to do a project with it to better understand how it works. So I set up a web application based on a smart contract deployed on the Rinkeby blockchain (testnet of the Ethereum blockchain). This application allow visitors to leave me a little message. Each message is stored in the blockchain, and is displayed on the website if the visitor connects his MetaMask wallet

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REACT
ALCHEMY
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SOLIDITY
ABI