How can I see the fields in Minecraft?

I'm playing minecraft right now and accidentally removed the fields from the sight money with some key combination or something. Does anyone know how I can undo this? You can see what I mean in the picture.

Press F1

You mean your inventory

Press F1 then everything should be normal again.

F1 and then everything is normal again.

Alt and F4

Joking aside, press F1