You enter it where other 1099R's are entered.
To enter your retirement income, Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your 1099R.
If you received military retirement income from DFAS they use a IRS Form 1099-R.
Go to this IRS website for what the Form 1099-R looks like - https://www.irs.gov/pub/irs-pdf/f1099r.pdf
To enter, edit or delete a form 1099-R -
Click on Federal Taxes (Personal using Home and Business)
Click on Wages and Income (Personal Income using Home and Business)
Click on I'll choose what I work on (if shown)
Scroll down to Retirement Plans and Social Security
On IRA, 401(k), Pension Plan Withdrawals (1099-R), click the start or update button
Or enter 1099-r in the Search box located in the upper right of the program screen. Click on Jump to 1099-R
Online editions -
On the screen Did you get a 1099-R in 2024? Click on Yes
On the screen Let's import your tax info Click on Change how I enter my form
On the screen How do you want to add your 1099‑R? Click on Type it in myself
On the screen Who gave you a 1099-R? select the type of 1099-R you received and Continue