Unable to sign transaction in custom RPC using walletconnect

As per documentation, I am using walletconnect with customRPC

https://docs.walletconnect.org/quick-start/dapps/web3-provider#custom-rpc-url

I am sharing some snippets to connect it with our custom provider called ‘eraswap’

import WalletConnectProvider from "@walletconnect/web3-provider";
import { providers } from "ethers"



export async function loadWallet() {
  //  Create WalletConnect Provider
  const walletConnectProvider = new WalletConnectProvider({
    rpc : { 5196 : 'https://testnet.eraswap.network'},
    infuraId: "b81341e3ab894360a84f3fa640ab985e" ,
    qrcode: true
  }); 
  await walletConnectProvider.enable();
  const provider = new providers.Web3Provider(walletConnectProvider)
  console.log(provider.getSigner())
  const wallet = await provider.getSigner()
  return wallet;
}

but I am getting these error

I am using modified version of https://test.walletconnect.org/ in which eraswap RPC network also exist

mention code is for added data in Ichaindata

{
    name: "Eraswap Testnet",
    short_name: "esn",
    chain: "ESN",
    network: "testnet",
    chain_id: 5196,
    network_id: 5196,
    rpc_url: "https://testnet.eraswap.network",
    native_currency: {
      symbol: "ES",
      name: "Eraswap",
      decimals: "18",
      contractAddress: "",
      balance: "",
    },
  },

the updated version of test wallet is https://esnwallet.vercel.app/. https://github.com/pranjal1127/eswallet/blob/master/src/constants/chains.ts#L4-L19

I have also tried all instructions of this following discussion https://github.com/ethers-io/ethers.js/issues/775

[vernonjohnson]

Big issue, needs to be fixed. Walletconnect is pretty much unusable on Polygon at this point

[ericHgorski]

Still experiencing this issue in 2022! Attempting to use a polygon RPC provider. Is there a fix in the works?