Add an RPC EVM Supported Network to Metamask

addRPCNetworkEthers.js

/** @see https://docs.metamask.io/guide/rpc-api.html#other-rpc-methods*/
async function changeNetwork(){
await ethereum.request({ method: 'wallet_addEthereumChain',
   params:[
      {chainId: "IN_HEXADECIMAL_FORM",
      chainName: "CHAIN_NAME",
      nativeCurrency: {
         name: "NATIVE_CURRENCY_NAME",
         symbol: "NATIVE_CURRENCY_SYMBOL",
         decimals: NATIVE_CURRENCY_DECIMALS //In number form
      },
      rpcUrls: ["BLOCKcHAIN_RPC_URL"],
      blockExplorerUrls?: ["BLOCKCHAIN_EXPLORER"]
   ]});
}

params.js

    const params = {
      chainId: toHex(chain.chainId), // A 0x-prefixed hexadecimal string
      chainName: chain.name,
      nativeCurrency: {
        name: chain.nativeCurrency.name,
        symbol: chain.nativeCurrency.symbol, // 2-6 characters long
        decimals: chain.nativeCurrency.decimals,
      },
      rpcUrls: chain.rpc,
      blockExplorerUrls: [ ((chain.explorers && chain.explorers.length > 0 && chain.explorers[0].url) ? chain.explorers[0].url : chain.infoURL) ]
    }

web3.js

    window.web3.eth.getAccounts((error, accounts) => {
      window.ethereum.request({
        method: 'wallet_addEthereumChain',
        params: [params, accounts[0]],
      })
      .then((result) => {
        console.log(result)
      })
      .catch((error) => {
        stores.emitter.emit(ERROR, error.message ? error.message : error)
        console.log(error)
      });
    })
  }