A putback is an offensive rebound immediately followed by a shot attempt by the rebounding player.
You can automate this entry with the a setting in the event assistant.
Select the Event Assistant from the options menu.
Turn on the feature. The Putback Fieldgoal is the option to enable.
Now add a missed shot to the game. What follows now is Player Select, Offensive Rebound, Add a shot (the Putback sequence) which saves selecting the same player twice for the rebound and the subsequent shot attempt.
Now select an offensive player (from the shooting team) to rebound.
Select the Offensive rebound button, missed shots will display the putback UI once you select rebound (the gray box with the player plus shot marker).
The UI will appear over the basket area on the court with an indication of which player got the rebound. If you now touch in that area the UI will vanish and the shot marker will appear where you are touching. You can release it or move and release to indicate a shot. You can also change the shot status as usual.
You can repeat the process if this is a missed shot and select player and rebound button again for additional putback.
If you start the process and then decide once the Putback UI is present that you do not want a putback shot, simply select a player for the next event and the UI will vanish.