read:https://wealthyaccountant.com/2018/12/18/deducting-gambling-losses-with-the-new-tax-bill/

I think this article explains the "theory" - see additional posts about how to notate the Notice 2015-21 Safe Harbor.

Your report the winnings, net the "Session losses" to get to the gain, the actual income. Then you can deduct losses up to gains when/if you can itemize.