'19 and'20, I did not file a Schedl D. However, I have accumulated losses from back in 2017. When filling out carryover info for 2020, which information should I use?

[RayW7]

If you have an unused prior-year loss, you can subtract it from this year’s net capital gains. You can report and deduct from your income a loss up to $3,000 — or $1,500 if married filing separately. You can carry over capital losses indefinitely.  

If your capital losses exceed your capital gains, the amount of the excess loss that you can claim to lower your income is the lesser of $3,000 ($1,500 if married filing separately) or your total net loss shown on line 21 of Schedule D (Form 1040). Claim the loss on line 6 of your Form 1040 or Form 1040-SR. If your net capital loss is more than this limit, you can carry the loss forward to later years. You may use the Capital Loss Carryover Worksheet found in Publication 550, Investment Income and Expenses or in the Instructions for Schedule D (Form 1040) PDF to figure the amount you can carry forward.

[jherrmann1]

Thank you!