The vast majority of spiders reproduce sexually. Semen is not introduced into the female's body through the genitals, but stored in special containers located on the pedipalps.

An excerpt from the article 28 facts about spiders

Only after these containers are filled with sperm does the male set out to look for a partner. During copulation, they are introduced into the female's external genitalia called epigynum, where fertilization occurs. This process was observed already in 1678 by Martin Lister, an English physician and naturalist.