You receive the Form 1099-R from the Payer of the account. If you did not receive the Form 1099-R then you have to contact the plan administrator to get the form.
Enter 1099-r in the Search box located in the upper right of the program screen. Click on Jump to 1099-R
On the screen Did you get a 1099-R in 2020? Click on Yes
On the next screen click on Continue
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