In the past, it seems that it was done for the purpose of exorcism and evil spirits.
However, recently, I don’t do it much at home because it’s troublesome to clean up after and because my faith has faded.
Mainly for events and small children.
I used to do it at home a few times when I was little.
Throw the beans outside and inside the house while saying, “Oni wa(=) soto, fortune wa(=) uchi.”
※”Oni(鬼)” = ogre, “Soto(外)” = outside
※”Fuku(福)” = Fuku, “Uchi(内)” = Inside

Also, there was a custom to eat as many beans as the number of years.
The base is roasted beans. When I was a child, it was around 10 grains, so it was okay, but it may be a little tough for adults.