In 2018 I sold my house and gave $174,000 to my ex wife. Not as apart of the divorce. I gifted it to her. Can I take one in a lifetime exception and not pay taxes?

I sold my house in 2018. I gifted the earnings to my ex wife. $174,000. It is my understanding that I have to file a form 709. I don't understand how the Once In a Lifetime Exception works. May I file a "once in a lifetime exception"?  May I use it to avoid having to pay taxes on the gift because it seems I have to pay 30% taxes, which I don't have. Thank you.