1099 forms come from the payors. So contact your banks, brokerage firms, pension administrators, SSA, etc. for them. I suggest you take a look at your 2023 tax returns and see what income you had to make sure you have all of your 2024 1099 forms.
You should also be able to log into your IRS account (create one at www.irs.gov if you don't already have one) and download your 1099s under "Wage and Income". Since your tax return is now delinquent, you should do that ASAP.
This is from Microsoft Co-Pilot:
To download your 1099 and W-2 forms from the IRS, follow these steps:
