It is usually not reccomended to top an auto flowering plant. You are on a timer from day 1 to grow as much of the plant as you can before it starts flowering. When you top the plant, it is a high stress event that can trigger it to flower early as well.
I prefer to LST autoflowers by pulling them down to create an even canopy. This exposes bottom branches to more light and you get multiple main colas vs only a few.
Keep going with your regular feedings and care. There is nothing much more to do at this stage.
Hope this helps.