From TurboTax: "The maximum your S corp can contribute to your SEP IRA is 25% of your W-2 compensation."

And: "The SECURE Act changed the deadline for a business to establish a qualified retirement plan to the business’ tax filing deadline, including extensions, for the tax year for which it intends to have a plan. This change is effective for 2020 and later taxable years."

There are plan types that allow for employer-only contributions, as a profit-sharing concept.

From the IRS:

https://www.irs.gov/retirement-plans/retirement-plan-faqs-regarding-contributions-s-corporation

These people need a Benefit Plan resource to guide them for 2022. For 2021, you have quite the problem in general for that 1120S.