The loss would be shown on the k-1 from the S-Corp to the shareholders. then the shareholder enters the k-1 info in their 1040. they also must complete form 7203 to show that they had sufficient basis to take the loss. they must also be at-risk. the loss can also be subject to passive activity rules. just because the S-Corp reports a loss does not mean the shareholder has an NOL other items of income and expense and the tax laws must be taken into account
the shareholders can use form 1045 schedule A for 2021 to see if they have an NOL
https://www.irs.gov/pub/irs-prior/f1045--2021.pdf
there would be an NOL if there is an excess of items of business loss reduced by items of business income
after reduction by the excess if any of nonbusiness income over nonbusiness deductions there are rules as to what items are business vs nonbusiness.
if you do not understand all this I suggest you use a professional.
