Item can't change in Minecraft, which key must I press now?

Hu
3

I just stupidly pressed any key on Minecraft and can't change the stones anymore. I always stay with the gray stones, I can't change, for example, to the grass. How do I solve the problem now?

Item can t change in Minecraft, which key must I press now
cl

In the inventory, the slot is next to the armor, to switch to F

pl

Press F

an

F ⠀⠀⠀⠀⠀