Error: call revert exception (method="getTotWaves()", errorArgs=null, errorName=null, errorSignature=null, reason=null, code=CALL_EXCEPTION,)

Question

when i click "Wave at me" button i encounter with this call revert error!.

here is the App.js

import React, { useEffect, useState } from "react";
import { ethers } from "ethers";
import './App.css';
import abi from './utils/WavePortal.json';

const App = () => {
  const [currentAccount, setCurrentAccount] = useState("");
  
  const contractAddress = "0xe50fc795e586B9Cd2f888142EBE5Fb9e59a26812";
  const contractABI = abi.abi;
  const getEthereumObject = () => window.ethereum;
  
  const checkIfWalletIsConnected = async () => {
    try {
      const { ethereum } = window;

      if (!ethereum) {
        console.log("Make sure you have metamask!");
        return;
      } else {
        console.log("We have the ethereum object", ethereum);
      }

      const accounts = await ethereum.request({ method: 'eth_requestAccounts' });

      if (accounts.length !== 0) {
        const account = accounts[0];
        console.log("Found an authorized account:", account);
        setCurrentAccount(account)
      } else {
        console.log("No authorized account found")
      }
    } catch (error) {
      console.log(error);
    }
  }

  const connectWallet = async () => {
    try {
      const  ethereum  = getEthereumObject();

      if (!ethereum) {
        alert("Get MetaMask!");
        return;
      }

      const accounts = await ethereum.request({ method: "eth_requestAccounts" });

      console.log("Connected", accounts[0]);
      setCurrentAccount(accounts[0]); 
    } catch (error) {
      console.log(error)
    }
  }

  const wave = async () => {
    try {
      const { ethereum } = window;

      if (ethereum) {
        const provider = new ethers.providers.Web3Provider(ethereum);
        const signer = provider.getSigner();
        const wavePortalContract = new ethers.Contract(contractAddress, contractABI, signer);

        var count = await wavePortalContract.getTotWaves();
        console.log("Retrieved total wave count...", count.toNumber());

        const waveTxn = await wavePortalContract.wave();
        console.log("Mining...", waveTxn.hash);

        await waveTxn.wait();
        

        console.log("Mined -- ", waveTxn.hash);

        count = await wavePortalContract.getTotWaves();
        console.log("Retrieved total wave count...", count.toNumber());
      } else {
        console.log("Ethereum object doesn't exist!");
      }
    } catch (error) {
      console.log(error)
    }
  }

  useEffect(() => {
    checkIfWalletIsConnected();
  }, [])
  

  return (
    
    <div className="mainContainer">
      

      <div className="dataContainer">
        <div className="header">
        <h1>👋</h1>
        <h2> Hey folks!</h2> 
        </div>

        <div className="bio">
        This is Dinesh! I am learning web3 and currently working on projects with the help of buildSpace. Connect your Ethereum wallet and wave at me!
        </div>

        <button className="waveButton" onClick={wave}>
          <h3>Wave at Me</h3>
        </button>

        {!currentAccount && (
          <button className="waveButton" onClick={connectWallet}>
            <h3>Connect Wallet</h3>
          </button>
        )}
      </div>
     
    </div>  
      
  );
  }
export default App;