Do I get a tax benefit for stock options I hold for a former employer company which is in liquidation?

Unfortunately my former employer company suffered too long under the conditions of the impacts of COVID-19 so is now in liquidation in 2020.  I had several years of incentive stock options (ISO's) as well as some option shares I purchased upon exit from the company in 2014.
Can I record those shares as a loss in the 2020 tax year?  The shares were not exercised.  And if so, how do I calculate the amount for what is now a $0 valuation?