Withholding Penalty

I had a large amount of taxable dividends that I wasn't expecting in 2021. I did not have enough withholding to cover the taxes from the dividends so the federal taxes I owe are about $12,500. Will I be penalized for not having enough withholding. When filling out my Turbo Tax return (which I haven't filed yet), I called a Turbo Tax agent and she said I would not be penalized but a friend said I would have a penalty.

 

If I do have a penalty, is there a form I can complete to plead my case of being new to this?

 

Thank you,

 

TimG3