Hi watttlyirs2021, thank you for posting an event question again.
Your unused tax year 2020 stock loss (capital loss) will be carryforward to tax year 2021 to offset any 2021 gain. If tax year 2021 has no gain, $3,000 the capital loss carryover from 2020 is used in tax year 2021. The remaining capital loss is carryover to tax year 2022.
You cannot pick and choose which future year(s) to apply the capital loss carryover.
What is a capital loss carryover?
https://ttlc.intuit.com/turbotax-support/en-us/help-article/investment-income/capital-loss-carryover/L8ozgt22F_US_en_US
Hope the above helps. Thank you much!
Kochu Kitty