Get the totalSupply() of a token (that is not ether) on the Ethereum blockchain

Unit1.pas

const Client: IWeb3 = TWeb3.Create('https://mainnet.infura.io/v3/your-project-id');
web3.eth.call(Client, '0xB8c77482e45F1F44dE1745F52C74426C631bDD52', 'symbol()', [], procedure(tup: TTuple; err: IError)
begin
  if Assigned(err) then
  begin
    TThread.Synchronize(nil, procedure
    begin
      MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)
    end);
    EXIT;
  end;
  const Symbol = tup.ToString;
  web3.eth.call(Client, '0xB8c77482e45F1F44dE1745F52C74426C631bDD52', 'totalSupply()', [], procedure(str: string; err: IError)
  begin
    TThread.Synchronize(nil, procedure
    begin
      if Assigned(err) then
        MessageDlg(err.Message, TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0)
      else
        ShowMessage(web3.eth.utils.fromWei(str, web3.eth.utils.ether) + ' ' + Symbol);
    end);
  end);
end);