Here is some info for you from IRS:

The Coronavirus Aid, Relief, and Economic Security Act (CARES Act) amended section 172(b)(1) to provide for a carryback of any net operating loss (NOL) arising in a taxable year beginning after December 31, 2017, and before January 1, 2021, to each of the five taxable years preceding the taxable year in which the loss arises (carryback period). Taxpayers may elect under section 172(b)(3) to waive the carryback period for NOLs arising in those years.

Here is link, so you can see the whole article:

https://www.irs.gov/newsroom/frequently-asked-questions-about-carrybacks-of-nols-for-taxpayers-who-h...