How to summon spirits? (Elden Ring)

I can’t understand either, I can call when a ghostly arch appears

Mind_Flow
Souls are summoned warriors, bots in short.
Ashes and a bell are needed, the bell is given after receiving the horse, at night in the church where the first merchant sits (this is not far from the start). When a white icon is visible in the lower left corner of the screen, the ashes can be used and warriors will appear, you can only summon one at a time.