This is snippet of my code.

    const getBalance = (userAddress: String) => {
    const provider = new Web3((window as any).web3.currentProvider);
    const bnbContract = new provider.eth.Contract(bnbTokenAbi, tokenAddress);
    bnbContract.methods.balanceOf(userAddress).call().then((res: any) => {
      setBalance(res);
    }).catch((err: any) => {
      console.log(err);
    });
  }

But only the catch function works, what's the reason?