Two things that some military people miss:
1) You must enter the fact that you were in the Military during 2020 in the MyInfo section....and also your rank. So you edit your personal Info in there and make sure that is set.
2) When you enter your Military W-2, there is a page after you enter the data in the main form, and this page shows a long list of checkboxes. You need to check the box in the middle of the page that says..."Active Duty Military" . That selection may not appear unless you've done #1 first.
(DO NOT USE your LES...you will enter your data wrong! Wait for your proper 2020 W-2 from DFAS)